QIAGEN RNeasy Lipid Tissue Mini Kit, Lipid Tissue Midi Kit RNA purification kit Handbook
Below you will find brief information for RNeasy Lipid Tissue Mini Kit, RNeasy Lipid Tissue Midi Kit. These kits are for the optimal lysis of tissues rich in fat, such as brain and adipose tissue, and purification of high-quality total RNA. They are also compatible with all other types of animal tissue. The kits effectively remove most DNA without DNase treatment, but optional on-column DNase digestion is available for sensitive applications.
Advertisement
Advertisement
1054915_HB 21.11.2008 9:08 Uhr Seite 1
RNeasy
®
Lipid Tissue Handbook
RNeasy Lipid Tissue Mini Kit
RNeasy Lipid Tissue Midi Kit
For purification of total RNA from fatty tissues and all other types of tissue
February 2009
Sample & Assay Technologies
1054915_HB 21.11.2008 9:08 Uhr Seite 2
QIAGEN Sample and Assay Technologies
QIAGEN is the leading provider of innovative sample and assay technologies, enabling the isolation and detection of contents of any biological sample. Our advanced, high-quality products and services ensure success from sample to result.
QIAGEN sets standards in:
■
Purification of DNA, RNA, and proteins
■
Nucleic acid and protein assays
■ microRNA research and RNAi
■
Automation of sample and assay technologies
Our mission is to enable you to achieve outstanding success and breakthroughs. For more information, visit www.qiagen.com.
1054915_HB 21.11.2008 9:08 Uhr Seite 3
Contents
Kit Contents
Storage
Quality Control
Product Use Limitations
Product Warranty and Satisfaction Guarantee
Technical Assistance
Safety Information
Introduction
Principle and procedure
Equipment and Reagents to Be Supplied by User
Important Notes
Determining the amount of starting material
Handling and storing starting material
Disrupting and homogenizing starting material
Protocols
■
■
Purification of Total RNA Using the RNeasy Lipid Tissue Mini Kit
Purification of Total RNA Using the RNeasy Lipid Tissue Midi Kit
Troubleshooting Guide
Appendix A: General Remarks on Handling RNA
Appendix B: Storage, Quantification, and Determination of Quality of RNA
Appendix C: Optional On-Column DNase Digestion with the RNase-Free
DNase Set
Ordering Information
14
19
24
28
30
33
35
10
11
12
7
9
10
6
7
5
5
4
5
4
4
RNeasy Lipid Tissue Handbook 02/2009
3
1054915_HB 21.11.2008 9:08 Uhr Seite 4
4
Kit Contents
RNeasy Lipid Tissue Kit
Catalog no.
Number of preps
RNeasy Mini Spin Columns
(each in a 2 ml Collection Tube)
RNeasy Midi Spin Columns
(each in a 15 ml Collection Tube)
Collection Tubes (1.5 ml)
Collection Tubes (2 ml)
Collection Tubes (15 ml)
QIAzol ® Lysis Reagent*
Buffer RW1*
Buffer RPE †
Handbook
(concentrate)
RNase-Free Water
Mini (50)
74804
50
50
–
50
50
–
50 ml
45 ml
11 ml
10 ml
1
Midi (10)
75842
10
–
10
–
–
10
50 ml
45 ml
11 ml
10 ml
1
†
* Contains a guanidine salt. Not compatible with disinfectants containing bleach. See page 6 for safety information.
Before using for the first time, add 4 volumes of ethanol (96–100%) as indicated on the bottle to obtain a working solution.
Note: QIAzol Lysis Reagent is delivered separately.
Storage
RNeasy Lipid Tissue Kits should be stored dry at room temperature (15–25°C). All components are stable for at least 9 months under these conditions.
QIAzol Lysis Reagent can be stored at room temperature or at 2–8°C.
Quality Control
In accordance with QIAGEN’s ISO-certified Quality Management System, each lot of
RNeasy Lipid Tissue Mini Kit and RNeasy Lipid Tissue Midi Kit is tested against predetermined specifications to ensure consistent product quality.
RNeasy Lipid Tissue Handbook 02/2009
1054915_HB 21.11.2008 9:08 Uhr Seite 5
Product Use Limitations
RNeasy Lipid Tissue Kits are intended for molecular biology applications. These products are neither intended for the diagnosis, prevention, or treatment of a disease, nor have they been validated for such use either alone or in combination with other products. Therefore, the performance characteristics of these products for clinical use
(i.e., diagnostic, prognostic, therapeutic, or blood banking) are unknown.
Product Warranty and Satisfaction Guarantee
QIAGEN guarantees the performance of all products in the manner described in our product literature. The purchaser must determine the suitability of the product for its particular use. Should any product fail to perform satisfactorily due to any reason other than misuse, QIAGEN will replace it free of charge or refund the purchase price. We reserve the right to change, alter, or modify any product to enhance its performance and design. If a QIAGEN ® product does not meet your expectations, simply call your local Technical Service Department or distributor. We will credit your account or exchange the product — as you wish. Separate conditions apply to QIAGEN scientific instruments, service products, and to products shipped on dry ice. Please inquire for more information.
A copy of QIAGEN terms and conditions can be obtained on request, and is also provided on the back of our invoices. If you have questions about product specifications or performance, please call QIAGEN Technical Services or your local distributor (see back cover or visit www.qiagen.com).
Technical Assistance
At QIAGEN, we pride ourselves on the quality and availability of our technical support.
Our Technical Service Departments are staffed by experienced scientists with extensive practical and theoretical expertise in sample and assay technologies and the use of
QIAGEN products. If you have any questions or experience any difficulties regarding
RNeasy Lipid Tissue Kits or QIAGEN products in general, please do not hesitate to contact us.
QIAGEN customers are a major source of information regarding advanced or specialized uses of our products. This information is helpful to other scientists as well as to the researchers at QIAGEN. We therefore encourage you to contact us if you have any suggestions about product performance or new applications and techniques.
For technical assistance and more information, please see our Technical Support
Center at www.qiagen.com/Support or call one of the QIAGEN Technical Service
Departments or local distributors (see back cover or visit www.qiagen.com).
RNeasy Lipid Tissue Handbook 02/2009
5
1054915_HB 21.11.2008 9:08 Uhr Seite 6
Safety Information
When working with chemicals, always wear a suitable lab coat, disposable gloves, and protective goggles. For more information, please consult the appropriate material safety data sheets (MSDSs). These are available online in convenient and compact PDF format at www.qiagen.com/Support/MSDS.aspx where you can find, view, and print the MSDS for each QIAGEN kit and kit component.
CAUTION: DO NOT add bleach or acidic solutions directly to the sample-preparation waste
QIAzol Lysis Reagent contains guanidine thiocyanate and Buffer RW1 contains a small amount of guanidine thiocyanate. Guanidine salts can form highly reactive compounds when combined with bleach. If liquid containing these buffers is spilt, clean with suitable laboratory detergent and water. If the spilt liquid contains potentially infectious agents, clean the affected area first with laboratory detergent and water, and then with 1% (v/v) sodium hypochlorite.
The following risk and safety phrases apply to the components of RNeasy Lipid Tissue
Kits.
QIAzol Lysis Reagent
Contains phenol, guanidine thiocyanate: toxic, corrosive. Risk and safety phrases:*
R23/24/25-32-34-48/20/21/22-68, S24/25-26-36/37/39-45
Buffer RW1
Contains ethanol: flammable. Risk phrase:* R10
24-hour emergency information
Emergency medical information in English, French, and German can be obtained
24 hours a day from:
Poison Information Center Mainz, Germany
Tel: +49-6131-19240
* R10: Flammable; R23/24/25: Toxic by inhalation, in contact with skin and if swallowed; R32: Contact with acids liberates very toxic gas; R34: Causes burns; R48/20/21/22: Harmful: danger of serious damage to health by prolonged exposure through inhalation, in contact with skin and if swallowed; R68:
Possible risk of irreversible effects; S24/25: Avoid contact with skin and eyes; S26: In case of contact with eyes, rinse immediately with plenty of water and seek medical advice; S36/37/39: Wear suitable protective clothing, gloves and eye/face protection; S45: In case of accident or if you feel unwell seek medical advice immediately (show the label where possible).
6
RNeasy Lipid Tissue Handbook 02/2009
1054915_HB 21.11.2008 9:08 Uhr Seite 7
Introduction
RNeasy Lipid Tissue Kits are designed for optimal lysis of tissues rich in fat, such as brain and adipose tissue, and purification of high-quality total RNA. The kits are also compatible with all other types of animal tissue. QIAGEN provides a wide range of other kits for purification of total RNA from different sample sources (visit www.qiagen.com/RNA).
Principle and procedure
RNeasy Lipid Tissue Kits integrate phenol/guanidine-based sample lysis and silicamembrane purification of total RNA. QIAzol Lysis Reagent, included in the kits, is a monophasic solution of phenol and guanidine thiocyanate, designed to facilitate lysis of fatty tissues and inhibit RNases. The high lysis efficiency of the reagent and the subsequent removal of contaminants by organic phase extraction enables use of larger amounts of tissue with RNeasy spin columns:
■
RNeasy Lipid Tissue Mini Kit — up to 100 mg of brain or adipose tissue per
RNeasy Mini spin column (up to 50 mg of other animal tissues)*
■
RNeasy Lipid Tissue Midi Kit — up to 500 mg of brain or adipose tissue per
RNeasy Midi spin column (up to 250 mg of other animal tissues)*
Tissue samples are homogenized in QIAzol Lysis Reagent. After addition of chloroform, the homogenate is separated into aqueous and organic phases by centrifugation. RNA partitions to the upper, aqueous phase while DNA partitions to the interphase and proteins to the lower, organic phase or the interphase.
The upper, aqueous phase is collected, and ethanol is added to provide appropriate binding conditions. The sample is then applied to an RNeasy spin column, where the total RNA binds to the membrane, and phenol and other contaminants are efficiently washed away. High-quality RNA is then eluted in RNase-free water (see flowcharts, next page).
With RNeasy Lipid Tissue Kits, all RNA molecules longer than 200 nucleotides are purified. The procedure provides an enrichment for mRNA since most RNAs <200 nucleotides (such as 5.8S rRNA, 5S rRNA, and tRNAs, which together comprise
15–20% of total RNA) are selectively excluded. The size distribution of the purified RNA is comparable to that obtained by centrifugation through a CsCl gradient or cushion, where small RNAs do not sediment efficiently. For purification of small RNA, including microRNA, from tissues and cells, we recommend using miRNeasy Kits (see ordering information, page 38).
* To ensure optimal RNA yields, the binding capacity of the RNeasy spin column must not be exceeded. For details, see the individual protocols.
RNeasy Lipid Tissue Handbook 02/2009
7
1054915_HB 21.11.2008 9:08 Uhr Seite 8
RNeasy Lipid Tissue
Mini Procedure
RNeasy Lipid Tissue
Midi Procedure
8
RNeasy Lipid Tissue Handbook 02/2009
1054915_HB 21.11.2008 9:08 Uhr Seite 9
Equipment and Reagents to Be Supplied by User
When working with chemicals, always wear a suitable lab coat, disposable gloves, and protective goggles. For more information, consult the appropriate material safety data sheets (MSDSs), available from the product supplier.
■
Chloroform
■
Ethanol (70% and 96–100%)*
■
Sterile, RNase-free pipet tips
■
Equipment for tissue disruption and homogenization (see page 12): we recommend either the TissueRuptor
® with TissueRuptor Disposable Probes or the
TissueLyser system (see ordering information, page 36)
■
For stabilization of RNA in tissues (see page 11): RNA later ® RNA Stabilization
Reagent or Allprotect Tissue Reagent (see ordering information, page 35) or liquid nitrogen and dry ice
Users of RNeasy Lipid Tissue Mini Kit
■
1.5 ml or 2 ml microcentrifuge tubes
■
Microcentrifuge(s) (with rotor for 2 ml tubes) for centrifugation at 4°C and at room temperature (15–25°C)
Users of RNeasy Lipid Tissue Midi Kit
■
10–15 ml centrifuge tubes
■
Laboratory centrifuge(s) (capable of 5000 x g) for centrifugation at 4°C and at room temperature (15–25°C) †
■
Optional: MaXtract High Density (see ordering information, page 36)
†
* Do not use denatured alcohol, which contains other substances such as methanol or methylethylketone.
All centrifugation steps are carried out in a conventional laboratory centrifuge (e.g., QIAGEN 96-Well-
Plate Centrifugation System; please inquire) with a swinging bucket rotor for 15 ml centrifuge tubes. The maximum speed of 3500–5000 rpm corresponds to 3000–5000 x g for most rotors. RNeasy Midi spin columns fit into 15 ml collection tubes supplied with the kit. These fit into the rotor of almost every standard laboratory centrifuge available. In the unlikely event that the tubes do not fit, RNeasy Midi spin columns can also be inserted into different 12–15 ml RNase-free glass or polypropylene tubes.
RNeasy Lipid Tissue Handbook 02/2009
9
1054915_HB 21.11.2008 9:08 Uhr Seite 10
Important Notes
Determining the amount of starting material
It is essential to use the correct amount of starting material in order to obtain optimal
RNA yield and purity. The maximum amount that can be used is determined by:
■
The type of tissue and its RNA content
■
The volume of QIAzol Lysis Reagent required for efficient lysis
■
The RNA binding capacity of the RNeasy spin column
When processing samples containing high amounts of RNA, less than the maximum amount of starting material shown in Table 1 should be used, so that the RNA binding capacity of the RNeasy spin column is not exceeded.
When processing samples containing low amounts of RNA, the maximum amount of starting material shown in Table 1 can be used. However, even though the RNA binding capacity of the RNeasy spin column is not reached, the maximum amount of starting material must not be exceeded. Otherwise, lysis will be incomplete and cellular debris may interfere with the binding of RNA to the RNeasy spin column membrane, resulting in lower RNA yield and purity.
More information on using the correct amount of starting material is given in the protocols. Table 2 shows expected RNA yields from various sources.
Table 1. RNeasy spin column specifications
Specification
Maximum binding capacity
Maximum loading volume
RNA size distribution
Minimum elution volume
Maximum amount of starting tissue
RNeasy Mini spin RNeasy Midi spin column column
100 µg RNA
700 µl
1 mg RNA
4 ml
RNA >200 nucleotides
30 µl
≤100 mg
RNA >200 nucleotides
150 µl
≤500 mg
Note: If the binding capacity of the RNeasy spin column is exceeded, RNA yields will not be consistent and may be reduced. If lysis of the starting material is incomplete,
RNA yields will be lower than expected, even if the binding capacity of the RNeasy spin column is not exceeded.
10
RNeasy Lipid Tissue Handbook 02/2009
1054915_HB 21.11.2008 9:08 Uhr Seite 11
Table 2. Typical yields of total RNA with RNeasy Lipid Tissue Kits
Mouse/rat tissue (10 mg)
Adipose tissue
Brain
Heart
Intestine
Kidney
Liver
Lung
Muscle
Skin
Spleen
Yield of total RNA (µg)*
0.5–2.5
5–20
5–25
10–60
5–40
15–80
5–15
5–35
2–5
15–100
* Amounts can vary due to factors such as species and developmental stage (especially with adipose tissues, large variations are possible due to developmental stage and location of the tissue). Since the RNeasy procedure enriches for mRNA and other RNA species >200 nucleotides, the total RNA yield does not include 5S rRNA, tRNA, and other low-molecular-weight RNAs, which make up 15–20% of total cellular
RNA.
Handling and storing starting material
RNA in harvested tissue is not protected until the sample is treated with RNA later RNA
Stabilization Reagent, flash-frozen, or disrupted and homogenized in the presence of
RNase-inhibiting or denaturing reagents. Otherwise, unwanted changes in the gene expression profile will occur. It is therefore important that tissue samples are immediately frozen in liquid nitrogen and stored at –70°C, or immediately immersed in RNA later
RNA Stabilization Reagent at room temperature. An alternative to RNA later RNA
Stabilization Reagent is Allprotect Tissue Reagent, which provides immediate stabilization of DNA, RNA, and protein in tissue samples at room temperature.
Note: RNAlater RNA Stabilization Reagent cannot be used to stabilize RNA in adipose tissue due to the high abundance of fat, but can be used to stabilize RNA in other fatty tissues such as brain. Allprotect Tissue Reagent can stabilize adipose and brain tissue.
The procedures for tissue harvesting and RNA protection should be carried out as quickly as possible. Frozen tissue samples should not be allowed to thaw during handling or weighing.
RNeasy Lipid Tissue Handbook 02/2009
11
1054915_HB 21.11.2008 9:08 Uhr Seite 12
Disrupting and homogenizing starting material
Efficient disruption and homogenization of the starting material is an absolute requirement for all total RNA purification procedures. Disruption and homogenization are 2 distinct steps:
■
Disruption: Complete disruption of plasma membranes of cells and organelles is absolutely required to release all the RNA contained in the sample. Incomplete disruption results in significantly reduced RNA yields.
■
Homogenization: Homogenization is necessary to reduce the viscosity of the lysates produced by disruption. Homogenization shears high-molecular-weight genomic DNA and other high-molecular-weight cellular components to create a homogeneous lysate. Incomplete homogenization results in inefficient binding of
RNA to the RNeasy spin column membrane and therefore significantly reduced
RNA yields.
Disruption and homogenization of tissue samples can be carried out rapidly and efficiently using either the TissueRuptor (for processing samples individually) or the
TissueLyser (for processing multiple samples simultaneously). Disruption and homogenization with the TissueRuptor or TissueLyser generally results in higher RNA yields than with other methods.
Disruption and homogenization using the TissueRuptor
The TissueRuptor is a rotor–stator homogenizer that thoroughly disrupts and simultaneously homogenizes single tissue samples in the presence of lysis buffer in
15–90 seconds, depending on the toughness and size of the sample. The blade of the
TissueRuptor disposable probe rotates at a very high speed, causing the sample to be disrupted and homogenized by a combination of turbulence and mechanical shearing.
For guidelines on using the TissueRuptor, refer to the TissueRuptor Handbook. For other rotor–stator homogenizers, refer to suppliers’ guidelines.
Disruption and homogenization using the TissueLyser
In bead-milling, tissues can be disrupted by rapid agitation in the presence of beads and lysis buffer. Disruption and simultaneous homogenization occur by the shearing and crushing action of the beads as they collide with the cells. The TissueLyser disrupts and homogenizes up to 48 tissue samples simultaneously when used in combination with the TissueLyser Adapter Set 2 x 24, which holds 48 x 2 ml microcentrifuge tubes containing stainless steel beads of 5 mm mean diameter. For guidelines on using the
TissueLyser, refer to the
TissueLyser Handbook. For other bead mills, refer to suppliers’ guidelines.
Note: Tungsten carbide beads react with QIAzol Lysis Reagent and must not be used to disrupt and homogenize tissues.
12
RNeasy Lipid Tissue Handbook 02/2009
1054915_HB 21.11.2008 9:08 Uhr Seite 13
The TissueLyser can also disrupt and homogenize up to 192 tissue samples simultaneously when used in combination with the TissueLyser Adapter Set 2 x 96, which holds 192 x 1.2 ml microtubes containing stainless steel beads of 5 mm mean diameter. In this case, we recommend using the RNeasy 96 Universal Tissue Kit, which provides high-throughput RNA purification from all types of tissue, including fatty tissues, in 96-well format and is based on the same technology as RNeasy Lipid Tissue
Kits. For ordering information, see page 38.
RNeasy Lipid Tissue Handbook 02/2009
13
1054915_HB 21.11.2008 9:08 Uhr Seite 14
Protocol: Purification of Total RNA Using the RNeasy
Lipid Tissue Mini Kit
Determining the correct amount of starting material
It is essential to use the correct amount of tissue in order to obtain optimal RNA yield and purity. With the RNeasy Lipid Tissue Mini Kit, a maximum of 100 mg brain or adipose tissue can generally be processed. For these tissues, the RNA binding capacity of the RNeasy Mini spin column and the lysing capacity of QIAzol Lysis Reagent will not be exceeded by these amounts. For other tissues, a maximum of 50 mg tissue can generally be used. For tissues with high RNA content such as liver, spleen, and thymus, we recommend using no more than 30 mg tissue to ensure optimal RNA yields and to avoid exceeding the binding capacity of the RNA spin column. Average RNA yields from various tissues are given in Table 2 (page 11).
If there is no information about the nature of your starting material, we recommend starting with no more than 30 mg tissue. Depending on RNA yield and purity, it may be possible to use up to 100 mg tissue in subsequent preparations.
Do not overload the RNeasy spin column, as this will significantly reduce RNA yield and quality.
Weighing tissue is the most accurate way to quantify the amount of starting material.
As a guide, a 4 mm cube (64 mm
3
) of most animal tissues weighs 70–85 mg.
Important points before starting
■
If using RNeasy Lipid Tissue Kits for the first time, read “Important Notes”
(page 10).
■
If working with RNA for the first time, read Appendix A (page 28).
■
If using the TissueRuptor, ensure that you are familiar with operating it by referring to the TissueRuptor User Manual and TissueRuptor Handbook.
■
If using the TissueLyser, ensure that you are familiar with operating it by referring to the operating instructions and
TissueLyser Handbook.
■
To freeze tissue for long-term storage (several months), flash-freeze in liquid nitrogen, and immediately transfer to –70°C. Do not allow tissues to thaw during weighing or handling prior to disruption in QIAzol Lysis Reagent. Homogenized tissue lysates from step 3 can also be stored at –70°C for several months. Incubate frozen lysates at 37°C in a water bath until completely thawed and salts are dissolved before continuing with step 4. Avoid prolonged incubation, which may compromise RNA integrity.
14
RNeasy Lipid Tissue Handbook 02/2009
1054915_HB 21.11.2008 9:08 Uhr Seite 15
■
Generally, DNase digestion is not required since integrated QIAzol and RNeasy technologies efficiently remove most of the DNA without DNase treatment.
However, further DNA removal may be necessary for certain RNA applications that are sensitive to very small amounts of DNA (e.g., TaqMan ® real-time RT-PCR analysis with a low-abundance target). In these cases, residual DNA can be removed by optional on-column DNase-digestion using the RNase-Free DNase Set
(see Appendix C, page 33). Alternatively, for real-time two-step RT-PCR applications, the QuantiTect ® Reverse Transcription Kit provides cDNA synthesis with integrated removal of genomic DNA contamination (see ordering information, page 37).
■
QIAzol Lysis Reagent and Buffer RW1 contain a guanidine salt and are therefore not compatible with disinfecting reagents containing bleach. See page 6 for safety information.
■
Except for phase separation (step 7), all protocol and centrifugation steps should be performed at room temperature (15–25°C). During the procedure, work quickly.
Things to do before starting
■
Buffer RPE is supplied as a concentrate. Before using for the first time, add
4 volumes of ethanol (96–100%) as indicated on the bottle to obtain a working solution.
■
If performing optional on-column DNase digestion, prepare DNase I stock solution as described in Appendix C (page 33).
Procedure
1.
If using the TissueLyser, add one stainless steel bead (5 mm mean diameter) per
2 ml microcentrifuge tube (not supplied). If working with tissues that are not stabilized in RNA later or Allprotect Reagent, place the tubes on dry ice.
2.
Excise the tissue sample from the animal or remove it from storage. Determine the amount of tissue. Do not use more than 100 mg. Proceed immediately to step 3.
Weighing tissue is the most accurate way to determine the amount.
If the tissue sample was stored in RNA later or Allprotect Reagent, remove it from the reagent using forceps and be sure to remove any excess reagent or crystals that may have formed.
RNA in harvested tissues is not protected until the tissues are treated with RNA later or Allprotect Reagent, flash-frozen, or disrupted and homogenized in step 3.
Frozen tissues should not be allowed to thaw during handling. The relevant procedures should be carried out as quickly as possible.
RNeasy Lipid Tissue Handbook 02/2009
15
1054915_HB 21.11.2008 9:08 Uhr Seite 16
3.
Disrupt the tissue and homogenize the lysate using either the TissueRupter (follow step 3a) or TissueLyser (follow step 3b).
See “Disrupting and homogenizing starting material”, page 12, for more details on disruption and homogenization.
Note: Incomplete homogenization leads to significantly reduced RNA yields and can cause clogging of the RNeasy spin column. Homogenization with the
TissueRupter or TissueLyser generally results in higher RNA yields than with other methods.
3a. Disruption and homogenization using the TissueRuptor:
■
Place the tissue in a suitably sized vessel containing 1 ml QIAzol Lysis
Reagent.
Note: Use a suitably sized vessel with sufficient extra headspace to accommodate foaming, which may occur during homogenization.
■
Generally, round-bottomed tubes allow more efficient disruption and homogenization than conical-bottomed tubes.
Place the tip of the disposable probe into the vessel and operate the
TissueRuptor at full speed until the lysate is uniformly homogeneous (usually
20–40 s). Proceed to step 4.
Note: To avoid damage to the TissueRuptor and disposable probe during operation, make sure the tip of the probe remains submerged in the buffer.
Foaming may occur during homogenization, especially of brain tissue. If this occurs, let the homogenate stand at room temperature for 2–3 min until the foam subsides before continuing with the procedure.
3b. Disruption and homogenization using the TissueLyser:
■
■
■
■
Place the tissues in the tubes prepared in step 1.
If the tubes were stored on dry ice, place them at room temperature. Then immediately add 1 ml QIAzol Lysis Reagent per tube.
Place the tubes in the TissueLyser Adapter Set 2 x 24.
Operate the TissueLyser for 2 min at 20 Hz.
■
The time depends on the tissue being processed and can be extended until the tissue is completely homogenized.
Disassemble the adapter set, rotate the rack of tubes so that the tubes nearest to the TissueLyser are now outermost, and reassemble the adapter set.
Operate the TissueLyser for another 2 min at 20 Hz.
■
Rearranging the tubes allows even homogenization.
Carefully pipet the lysates into new microcentrifuge tubes (not supplied).
Proceed to step 4.
Do not reuse the stainless steel beads.
16
RNeasy Lipid Tissue Handbook 02/2009
1054915_HB 21.11.2008 9:08 Uhr Seite 17
4.
Place the tube containing the homogenate on the benchtop at room temperature
(15–25°C) for 5 min.
This step promotes dissociation of nucleoprotein complexes.
5.
Add 200 µl chloroform. Securely cap the tube containing the homogenate, and shake it vigorously for 15 s.
Thorough mixing is important for subsequent phase separation.
6.
Place the tube containing the homogenate on the benchtop at room temperature for 2–3 min.
7.
Centrifuge at 12,000 x g for 15 min at 4°C. After centrifugation, heat the centrifuge to room temperature (15–25°C) if the same centrifuge will be used in the later steps of this procedure.
After centrifugation, the sample separates into 3 phases: an upper, colorless, aqueous phase containing RNA; a white interphase; and a lower, red, organic phase. For tissues with an especially high fat content, an additional, clear phase may be visible below the red, organic phase. The volume of the aqueous phase should be approximately 600 µl.
8.
Transfer the upper, aqueous phase to a new tube (not supplied). Add 1 volume
(usually 600 µl) of 70% ethanol, and mix thoroughly by vortexing. Do not centrifuge. Proceed immediately to step 9.
Note: The volume of lysate may be less than 600 µl due to loss during homogenization and centrifugation.
Precipitates may be visible after addition of ethanol. Resuspend precipitates completely by vigorous shaking, and proceed immediately to step 9.
9.
Transfer up to 700 µl of the sample to an RNeasy Mini spin column placed in a 2 ml
( collection tube (supplied). Close the lid gently, and centrifuge for 15 s at
ⱖ
8000 x
ⱖ
10,000 rpm) at room temperature (15–25°C). Discard the flow-through.* g
Reuse the collection tube in step 10.
10. Repeat step 9 using the remainder of the sample. Discard the flow-through.*
Reuse the collection tube in step 11.
Optional: If performing optional on-column DNase digestion (see “Important points before starting”), follow steps C1–C4 (page 33) after performing this step.
* Flow-through contains QIAzol Lysis Reagent and is therefore not compatible with bleach. See page 6 for safety information.
RNeasy Lipid Tissue Handbook 02/2009
17
1054915_HB 21.11.2008 9:08 Uhr Seite 18
11. Add 700 µl Buffer RW1 to the RNeasy spin column. Close the lid gently, and centrifuge for 15 s at
ⱖ
8000 x g (
ⱖ
10,000 rpm) to wash the membrane. Discard the flow-through.*
Reuse the collection tube in step 12.
After centrifugation, carefully remove the RNeasy spin column from the collection tube so that the column does not contact the flow-through. Be sure to empty the collection tube completely.*
Skip this step if performing optional on-column DNase digestion (page 33).
12. Add 500 µl Buffer RPE to the RNeasy spin column. Close the lid gently, and centrifuge for 15 s at
ⱖ
8000 x g (
ⱖ
10,000 rpm) to wash the membrane. Discard the flow-through.
Reuse the collection tube in step 13.
Note: Buffer RPE is supplied as a concentrate. Ensure that ethanol is added to
Buffer RPE before use (see “Things to do before starting”, page 15).
13. Add 500 µl Buffer RPE to the RNeasy spin column. Close the lid gently, and centrifuge for 2 min at
ⱖ
8000 x g (
ⱖ
10,000 rpm) to wash the membrane.
The long centrifugation dries the spin column membrane, ensuring that no ethanol is carried over during RNA elution. Residual ethanol may interfere with downstream reactions.
Note: After centrifugation, carefully remove the RNeasy spin column from the collection tube so that the column does not contact the flow-through. Otherwise, carryover of ethanol will occur.
14. Optional: Place the RNeasy spin column in a new 2 ml collection tube (supplied), and discard the old collection tube with the flow-through. Close the lid gently, and centrifuge at full speed for 1 min.
Perform this step to eliminate any possible carryover of Buffer RPE, or if residual flow-through remains on the outside of the RNeasy spin column after step 13.
15. Place the RNeasy spin column in a new 1.5 ml collection tube (supplied). Add
30–50 µl RNase-free water directly to the spin column membrane. Close the lid gently. To elute the RNA, centrifuge for 1 min at
ⱖ
8000 x g (
ⱖ
10,000 rpm).
16. Repeat step 15 using another volume of RNase-free water, or using the eluate from step 15 (if high RNA concentration is required). Reuse the collection tube from step
15.
If using the eluate from step 15, the RNA yield will be 15–30% less than that obtained using a second volume of RNase-free water, but the final RNA concentration will be higher.
* Flow-through contains Buffer RW1 and is therefore not compatible with bleach. See page 6 for safety information.
18
RNeasy Lipid Tissue Handbook 02/2009
1054915_HB 21.11.2008 9:08 Uhr Seite 19
Protocol: Purification of Total RNA Using the RNeasy
Lipid Tissue Midi Kit
Determining the correct amount of starting material
It is essential to use the correct amount of tissue in order to obtain optimal RNA yield and purity. With the RNeasy Lipid Tissue Midi Kit, a maximum of 500 mg brain or adipose tissue can generally be processed. For these tissues, the RNA binding capacity of the RNeasy Midi spin column and the lysing capacity of QIAzol Lysis Reagent will not be exceeded by these amounts. For other tissues, a maximum of 250 mg tissue can generally be used. For tissues with high RNA content such as liver, spleen, and thymus, we recommend using no more than 150 mg tissue to ensure optimal RNA yields and to avoid exceeding the binding capacity of the RNA spin column. Average RNA yields from various tissues are given in Table 2 (page 11).
If there is no information about the nature of your starting material, we recommend starting with no more than 150 mg tissue. Depending on RNA yield and purity, it may be possible to use up to 500 mg tissue in subsequent preparations.
Do not overload the RNeasy spin column, as this will significantly reduce RNA yield and quality.
Weighing tissue is the most accurate way to quantify the amount of starting material.
As a guide, a 6 mm cube (216 mm
3
) of most animal tissues weighs 240–280 mg.
Important points before starting
■
If using RNeasy Lipid Tissue Kits for the first time, read “Important Notes”
(page 10).
■
If working with RNA for the first time, read Appendix A (page 28).
■
If using the TissueRuptor, ensure that you are familiar with operating it by referring to the TissueRuptor User Manual and TissueRuptor Handbook.
■
To freeze tissue for long-term storage (several months), flash-freeze in liquid nitrogen, and immediately transfer to –70°C. Do not allow tissues to thaw during weighing or handling prior to disruption in QIAzol Lysis Reagent. Homogenized tissue lysates from step 3 can also be stored at –70°C for several months. Incubate frozen lysates at 37°C in a water bath until completely thawed and salts are dissolved before continuing with step 4. Avoid prolonged incubation, which may compromise RNA integrity.
RNeasy Lipid Tissue Handbook 02/2009
19
1054915_HB 21.11.2008 9:08 Uhr Seite 20
■
Generally, DNase digestion is not required since integrated QIAzol and RNeasy technologies efficiently remove most of the DNA without DNase treatment.
However, further DNA removal may be necessary for certain RNA applications that are sensitive to very small amounts of DNA (e.g., TaqMan real-time
RT-PCR analysis with a low-abundance target). In these cases, residual DNA can be removed by optional on-column DNase-digestion using the RNase-Free DNase
Set (see Appendix C, page 33). Alternatively, for real-time two-step RT-PCR applications, the QuantiTect Reverse Transcription Kit provides cDNA synthesis with integrated removal of genomic DNA contamination (see ordering information, page 37).
■
QIAzol Lysis Reagent and Buffer RW1 contain a guanidine salt and are therefore not compatible with disinfecting reagents containing bleach. See page 6 for safety information.
■
Except for phase separation (step 7), all protocol and centrifugation steps should be performed at room temperature (15–25°C). During the procedure, work quickly.
Things to do before starting
■
Buffer RPE is supplied as a concentrate. Before using for the first time, add
4 volumes of ethanol (96–100%) as indicated on the bottle to obtain a working solution.
■
If performing optional on-column DNase digestion, prepare DNase I stock solution as described in Appendix C (page 33).
Procedure
1.
Excise the tissue sample from the animal or remove it from storage. Determine the amount of tissue. Do not use more than 500 mg. Proceed immediately to step 2.
Weighing tissue is the most accurate way to determine the amount.
If the tissue sample was stored in RNA later or Allprotect Reagent, remove it from the reagent using forceps and be sure to remove any excess reagent or crystals that may have formed.
RNA in harvested tissues is not protected until the tissues are treated with RNA later or Allprotect Reagent, flash-frozen, or disrupted and homogenized in step 3.
Frozen tissues should not be allowed to thaw during handling. The relevant procedures should be carried out as quickly as possible.
2.
Place the tissue in a suitably sized vessel containing 5 ml QIAzol Lysis Reagent.
Note: Use a suitably sized vessel with sufficient extra headspace to accommodate foaming, which may occur during homogenization.
20
RNeasy Lipid Tissue Handbook 02/2009
1054915_HB 21.11.2008 9:08 Uhr Seite 21
Generally, round-bottomed tubes allow more efficient disruption and homogenization than conical-bottomed tubes.
3.
Place the tip of the TissueRuptor disposable probe into the vessel and operate the
TissueRuptor at full speed until the lysate is uniformly homogeneous (usually
30–60 s).
Note: To avoid damage to the TissueRuptor and disposable probe during operation, make sure the tip of the probe remains submerged in the buffer.
Note: Incomplete homogenization leads to significantly reduced RNA yields and can cause clogging of the RNeasy spin column.
Foaming may occur during homogenization, especially of brain tissue. If this occurs, let the homogenate stand at room temperature for 2–3 min until the foam subsides before continuing with the procedure.
4.
Place the tube containing the homogenate on the benchtop at room temperature
(15–25°C) for 5 min.
This step promotes dissociation of nucleoprotein complexes.
5.
Add 1 ml chloroform. Securely cap the tube containing the homogenate, and shake it vigorously for 15 s.
Thorough mixing is important for subsequent phase separation.
6.
Place the tube containing the homogenate on the benchtop at room temperature for 2–3 min.
7.
Centrifuge at 5000 x g for 15 min at 4°C. After centrifugation, heat the centrifuge to room temperature (15–25°C) if the same centrifuge will be used in the later steps of this procedure.
After centrifugation, the sample separates into 3 phases: an upper, colorless, aqueous phase containing RNA; a white interphase; and a lower, red, organic phase. For tissues with an especially high fat content, an additional, clear phase may be visible below the red, organic phase. The volume of the aqueous phase should be approximately 3 ml.
Optional: Alternatively, centrifuge the homogenate in a 15 ml or 50 ml MaXtract
High Density tube (for ordering information, see page 36). The MaXtract tube contains a gel which forms a stable barrier between the aqueous phase and the other phases after centrifugation.
8.
Transfer the upper, aqueous phase to a new tube (not supplied). Add 1 volume
(usually 3 ml) of 70% ethanol, and mix thoroughly by vortexing. Do not centrifuge.
Proceed immediately to step 9.
Note: The volume of lysate may be less than 3 ml due to loss during homogenization and centrifugation.
Precipitates may be visible after addition of ethanol. Resuspend precipitates completely by vigorous shaking, and proceed immediately to step 9.
RNeasy Lipid Tissue Handbook 02/2009
21
1054915_HB 21.11.2008 9:08 Uhr Seite 22
9.
Transfer up to 4 ml of the sample to an RNeasy Midi spin column placed in a 15 ml collection tube (supplied). Close the lid gently, and centrifuge for 5 min at
3000–5000 x g at room temperature (15–25°C). Discard the flow-through.*
Reuse the collection tube in step 10.
10. Repeat step 10 using the remainder of the sample (up to 4 ml). Discard the flowthrough.*
Reuse the collection tube in step 11.
Optional: If performing optional on-column DNase digestion (see “Important points before starting”), follow steps C1–C4 (page 33) after performing this step.
11. Add 4 ml Buffer RW1 to the RNeasy spin column. Close the lid gently, and centrifuge for 5 min at 3000–5000 x g to wash the membrane. Discard the flowthrough.*
Reuse the collection tube in step 12.
Skip this step if performing optional on-column DNase digestion (page 33).
12. Add 2.5 ml Buffer RPE to the RNeasy spin column. Close the lid gently, and centrifuge for 2 min at 3000–5000 x g to wash the membrane. Discard the flowthrough.
Reuse the collection tube in step 13.
Note: Buffer RPE is supplied as a concentrate. Ensure that ethanol is added to
Buffer RPE before use (see “Things to do before starting”, page 20).
13. Add 2.5 ml Buffer RPE to the RNeasy spin column. Close the lid gently, and centrifuge for 5 min at 3000–5000 x g to wash the membrane.
The long centrifugation dries the spin column membrane, ensuring that no ethanol is carried over during RNA elution. Residual ethanol may interfere with downstream reactions.
Note: After centrifugation, carefully remove the RNeasy spin column from the collection tube so that the column does not contact the flow-through. Otherwise, carryover of ethanol will occur.
14. Place the RNeasy spin column in a new 15 ml collection tube (supplied). Add the appropriate volume of RNase-free water (see Table 3) directly to the spin column membrane. Close the lid gently. To elute the RNA, wait for 1 min and then centrifuge for 3 min at 3000–5000 x g.
* Flow-through contains QIAzol Lysis Reagent or Buffer RW1 and is therefore not compatible with bleach.
See page 6 for safety information.
22
RNeasy Lipid Tissue Handbook 02/2009
1054915_HB 21.11.2008 9:08 Uhr Seite 23
Table 3. Volumes of RNase-Free Water for RNA Elution
Expected total RNA yield
ⱕ
150 µg
150 µg – 1 mg
RNase-free water
150 µl
250 µl
15. Repeat step 14 using another volume of RNase-free water, or using the eluate from step 14 (if high RNA concentration is required). Reuse the collection tube from step 14.
If using the eluate from step 14, the RNA yield will be 15–30% less than that obtained using a second volume of RNase-free water, but the final RNA concentration will be higher.
RNeasy Lipid Tissue Handbook 02/2009
23
1054915_HB 21.11.2008 9:08 Uhr Seite 24
Troubleshooting Guide
This troubleshooting guide may be helpful in solving any problems that may arise. For more information, see also the Frequently Asked Questions page at our Technical
Support Center: www.qiagen.com/FAQ/FAQList.aspx. The scientists in QIAGEN
Technical Services are always happy to answer any questions you may have about either the information and protocols in this handbook or sample and assay technologies
(for contact information, see back cover or visit www.qiagen.com).
Comments and suggestions
Phases do not separate completely
a) No chloroform added or chloroform not pure b) Homogenate not sufficiently mixed before centrifugation c) Organic solvents in samples used for RNA purification
Make sure to add chloroform that does not contain isoamyl alcohol or other additives.
After addition of chloroform (step 5), the homogenate must be vigorously shaken. If the phases are not well separated, shake the tube vigorously for at least 15 s, and repeat the incubation and centrifugation in steps 6 and 7.
Make sure that the starting sample does not contain organic solvents (e.g., ethanol,
DMSO), strong buffers, or alkaline reagents.
These can interfere with the phase separation.
Clogged RNeasy spin column
a) Inefficient disruption and/or homogenization b) Too much starting material
See “Disrupting and homogenizing starting material” (page 12) for details on disruption and homogenization methods.
Increase g-force and centrifugation time if necessary.
In subsequent preparations, reduce the amount of starting material (see page 10 and protocol, page 14 or 19) and/or increase the homogenization time.
In subsequent preparations, reduce the amount of starting material. It is essential to use the correct amount of starting material
(see page 10 and protocol, page 14 or 19).
24
RNeasy Lipid Tissue Handbook 02/2009
1054915_HB 21.11.2008 9:08 Uhr Seite 25
Comments and suggestions
c) Centrifugation temperature too low Except for phase separation (step 7), all centrifugation steps should be performed at
15–25°C. Some centrifuges may cool to below 20°C even when set at 20°C. This can cause formation of precipitates that can clog the RNeasy spin column. If this happens, set the centrifugation temperature to 25°C. Warm the ethanol-containing lysate to 37°C before transferring to the
RNeasy spin column.
Low RNA yield
a) Insufficient disruption and homogenization b) Too much starting material
See “Disrupting and homogenizing starting material” (page 12) for details on disruption and homogenization methods.
In subsequent preparations, reduce the amount of starting material. It is essential to use the correct amount of starting material
(see page 10 and protocol, page 14 or 19).
c) d)
RNA bound spin column membrane
Centrifugation temperature too low
Repeat RNA elution, but incubate the
RNeasy spin column on the benchtop for
10 min with RNase-free water before centrifuging.
Except for phase separation (step 7), all centrifugation steps should be performed at
15–25°C. Some centrifuges may cool to below 20°C even when set at 20°C. This can cause formation of precipitates that can clog the RNeasy spin column. If this happens, set the centrifugation temperature to 25°C. Warm the ethanol-containing lysate to 37°C before transferring to the
RNeasy spin column.
Low or no recovery of RNA (RNeasy Lipid Tissue Mini Kit)
RNase-free water incorrectly dispensed Add RNase-free water to the center of the
RNeasy spin column membrane to ensure that the membrane is completely covered.
RNeasy Lipid Tissue Handbook 02/2009
25
1054915_HB 21.11.2008 9:08 Uhr Seite 26
Comments and suggestions
Low A
260
/ A
280 value
a) Not enough QIAzol Lysis In subsequent preparations, reduce the
Reagent used for homogenization amount of starting material and/or increase the volume of QIAzol Lysis Reagent and the homogenization time.
b) Sample not incubated for 5 min after homogenization c) Water used to dilute RNA for A
260
/ A
280 measurement
Place the sample at room temperature
(15–25°C) for 5 min after homogenization, as indicated in the protocol (step 4). This step is important to promote dissociation of nucleoprotein complexes.
Use 10 mM Tris·Cl, pH 7.5, not RNase-free water, to dilute the sample before measuring purity (see Appendix B, page 30).
RNA degraded
a) Inappropriate handling of starting material b) RNase contamination
For frozen tissue samples, ensure that they were flash-frozen immediately in liquid nitrogen and properly stored at –70°C.
Perform the RNeasy procedure quickly, especially the first few steps.
See Appendix A (page 28) and “Handling and storing starting material” (page 11).
Although all RNeasy buffers have been tested and are guaranteed RNase-free,
RNases can be introduced during use. Be certain not to introduce any RNases during the RNeasy procedure or later handling. See
Appendix A (page 28) for general remarks on handling RNA.
Do not put RNA samples into a vacuum dryer that has been used in DNA preparation where RNases may have been used.
DNA contamination in downstream experiments
a) Phase separation performed at too high a temperature
The phase separation (step 7) should be performed at 4°C to allow optimal phase separation and removal of genomic DNA from the aqueous phase. Make sure that the centrifuge does not heat above 10°C during the centrifugation.
26
RNeasy Lipid Tissue Handbook 02/2009
1054915_HB 21.11.2008 9:08 Uhr Seite 27
Comments and suggestions
b) Interphase contamination of aqueous phase
Contamination of the aqueous phase with the interphase results in an increased DNA content in the RNA eluate. Make sure to transfer the aqueous phase without interphase contamination.
c) Not enough QIAzol Lysis Reagent In subsequent preparations, reduce the used for homogenization amount of starting material and/or increase the volume of QIAzol Lysis Reagent and the homogenization time.
d) e)
Organic solvents in samples used for RNA purification
No DNase treatment
Make sure that the starting sample does not contain organic solvents (e.g., ethanol,
DMSO), strong buffers, or alkaline reagents.
These can interfere with the phase separation.
Perform optional on-column DNase digestion using the RNase-Free DNase Set
(Appendix C, page 33) at step 10 of the protocol.
RNA does not perform well in downstream experiments
a) Salt carryover during elution b) Ethanol carryover
Ensure that Buffer RPE is at 20–30°C.
During the second wash with Buffer RPE (step
13), be sure to dry the RNeasy spin column membrane by centrifuging at ⱖ
8000 x g
( ⱖ
10,000 rpm) for 2 min at 15–25°C
(RNeasy Lipid Tissue Mini Kit) or at
3000–5000 x g for 5 min at 15–25°C
(RNeasy Lipid Tissue Midi Kit). After centrifugation, carefully remove the column from the collection tube so that the column does not contact the flow-through.
Otherwise, carryover of ethanol will occur.
To eliminate any chance of possible ethanol carryover with the RNeasy Lipid Tissue Mini
Kit, place the RNeasy Mini spin column in a new 2 ml collection tube and perform the optional 1-min centrifugation step as described in step 14 of the protocol.
RNeasy Lipid Tissue Handbook 02/2009
27
1054915_HB 21.11.2008 9:08 Uhr Seite 28
Appendix A: General Remarks on Handling RNA
Handling RNA
Ribonucleases (RNases) are very stable and active enzymes that generally do not require cofactors to function. Since RNases are difficult to inactivate and even minute amounts are sufficient to destroy RNA, do not use any plasticware or glassware without first eliminating possible RNase contamination. Great care should be taken to avoid inadvertently introducing RNases into the RNA sample during or after the purification procedure. In order to create and maintain an RNase-free environment, the following precautions must be taken during pretreatment and use of disposable and nondisposable vessels and solutions while working with RNA.
General handling
Proper microbiological, aseptic technique should always be used when working with
RNA. Hands and dust particles may carry bacteria and molds and are the most common sources of RNase contamination. Always wear latex or vinyl gloves while handling reagents and RNA samples to prevent RNase contamination from the surface of the skin or from dusty laboratory equipment. Change gloves frequently and keep tubes closed whenever possible. Keep purified RNA on ice when aliquots are pipetted for downstream applications.
Disposable plasticware
The use of sterile, disposable polypropylene tubes is recommended throughout the procedure. These tubes are generally RNase-free and do not require pretreatment to inactivate RNases.
Nondisposable plasticware
Nondisposable plasticware should be treated before use to ensure that it is RNase-free.
Plasticware should be thoroughly rinsed with 0.1 M NaOH, 1 mM EDTA* followed by
RNase-free water (see ”Solutions”, page 29). Alternatively, chloroform-resistant plasticware can be rinsed with chloroform* to inactivate RNases.
* When working with chemicals, always wear a suitable lab coat, disposable gloves, and protective goggles. For more information, consult the appropriate material safety data sheets (MSDSs), available from the product supplier.
28
RNeasy Lipid Tissue Handbook 02/2009
1054915_HB 21.11.2008 9:08 Uhr Seite 29
Glassware
Glassware should be treated before use to ensure that it is RNase-free. Glassware used for RNA work should be cleaned with a detergent,* thoroughly rinsed, and oven baked at 240°C for at least 4 hours (overnight, if more convenient) before use. Autoclaving alone will not fully inactivate many RNases. Alternatively, glassware can be treated with
DEPC* (diethyl pyrocarbonate). Fill glassware with 0.1% DEPC (0.1% in water), allow to stand overnight (12 hours) at 37°C, and then autoclave or heat to 100°C for
15 minutes to eliminate residual DEPC.
Electrophoresis tanks
Electrophoresis tanks should be cleaned with detergent solution (e.g., 0.5% SDS),* thoroughly rinsed with RNase-free water, and then rinsed with ethanol † and allowed to dry.
Solutions
Solutions (water and other solutions) should be treated with 0.1% DEPC. DEPC is a strong, but not absolute, inhibitor of RNases. It is commonly used at a concentration of
0.1% to inactivate RNases on glass or plasticware or to create RNase-free solutions and water. DEPC inactivates RNases by covalent modification. Add 0.1 ml DEPC to 100 ml of the solution to be treated and shake vigorously to bring the DEPC into solution. Let the solution incubate for 12 hours at 37°C. Autoclave for 15 minutes to remove any trace of DEPC. DEPC will react with primary amines and cannot be used directly to treat
Tris* buffers. DEPC is highly unstable in the presence of Tris buffers and decomposes rapidly into ethanol and CO
2
. When preparing Tris buffers, treat water with DEPC first, and then dissolve Tris to make the appropriate buffer. Trace amounts of DEPC will modify purine residues in RNA by carbethoxylation. Carbethoxylated RNA is translated with very low efficiency in cell-free systems. However, its ability to form DNA:RNA or
RNA:RNA hybrids is not seriously affected unless a large fraction of the purine residues have been modified. Residual DEPC must always be eliminated from solutions or vessels by autoclaving or heating to 100°C for 15 minutes.
Note: RNeasy buffers are guaranteed RNase-free without using DEPC treatment and are therefore free of any DEPC contamination.
†
* When working with chemicals, always wear a suitable lab coat, disposable gloves, and protective goggles. For more information, consult the appropriate material safety data sheets (MSDSs), available from the product supplier.
Plastics used for some electrophoresis tanks are not resistant to ethanol. Take proper care and check the supplier’s instructions.
RNeasy Lipid Tissue Handbook 02/2009
29
1054915_HB 21.11.2008 9:08 Uhr Seite 30
Appendix B: Storage, Quantification, and
Determination of Quality of RNA
Storage of RNA
Purified RNA may be stored at –20°C or –70°C in RNase-free water. Under these conditions, no degradation of RNA is detectable after 1 year.
Quantification of RNA
The concentration of RNA should be determined by measuring the absorbance at
260 nm (
A
260
) in a spectrophotometer (see “Spectrophotometric quantification of RNA” below). For small amounts of RNA, however, it may be difficult to determine amounts photometrically. Small amounts of RNA can be quantified using the QIAxcel ™ system
(www.qiagen.com/QIAxcel) or Agilent
®
2100 bioanalyzer, quantitative RT-PCR, or fluorometric quantification.
Spectrophotometric quantification of RNA
To ensure significance, A
260 readings should be greater than 0.15. An absorbance of
1 unit at 260 nm corresponds to 44 µg of RNA per ml ( A
260
=1
→ 44 µg/ml). This relation is valid only for measurements at a neutral pH. Therefore, if it is necessary to dilute the RNA sample, this should be done in a buffer with neutral pH.* As discussed below (see “Purity of RNA”, page 31), the ratio between the absorbance values at 260 and 280 nm gives an estimate of RNA purity.
When measuring RNA samples, be certain that cuvettes are RNase-free, especially if the RNA is to be recovered after spectrophotometry. This can be accomplished by washing cuvettes with 0.1 M NaOH, 1 mM EDTA,* followed by washing with
RNase-free water (see “Solutions”, page 29). Use the buffer in which the RNA is diluted to zero the spectrophotometer. An example of the calculation involved in RNA quantification is shown below:
Volume of RNA sample = 100 µl
Dilution = 10 µl of RNA sample + 490 µl of 10 mM Tris·Cl,* pH 7.0
(1/50 dilution)
Measure absorbance of diluted sample in a 1 ml cuvette (RNase-free)
A
260
= 0.2
Concentration of RNA sample = 44 µg/ml x A
260 x dilution factor
= 44 µg/ml x 0.2 x 50
= 440 µg/ml
* When working with chemicals, always wear a suitable lab coat, disposable gloves, and protective goggles. For more information, consult the appropriate material safety data sheets (MSDSs), available from the product supplier.
30
RNeasy Lipid Tissue Handbook 02/2009
1054915_HB 21.11.2008 9:08 Uhr Seite 31
Total amount = concentration x volume in milliliters
= 440 µg/ml x 0.1 ml
= 44 µg of RNA
Purity of RNA
The ratio of the readings at 260 nm and 280 nm ( A
260
/ A
280
) provides an estimate of the purity of RNA with respect to contaminants that absorb in the UV spectrum, such as protein. However, the A
260
/ A
280 ratio is influenced considerably by pH. Since water is not buffered, the pH and the resulting in a lower A
260
/ A
280
A
260
/ A
280 ratio can vary greatly. Lower pH results ratio and reduced sensitivity to protein contamination.* For accurate values, we recommend measuring absorbance in 10 mM Tris·Cl, pH 7.5. Pure
RNA has an A
260
/ A
280 ratio of 1.9–2.1
† in 10 mM Tris·Cl, pH 7.5. Always be sure to calibrate the spectrophotometer with the same solution used for dilution.
For determination of RNA concentration, however, we recommend dilution of the sample in a buffer with neutral pH since the relationship between absorbance and concentration ( A
260 reading of 1 = 44 µg/ml RNA) is based on an extinction coefficient calculated for RNA at neutral pH (see “Spectrophotometric quantification of RNA”, page 30).
DNA contamination
No currently available purification method can guarantee that RNA is completely free of DNA, even when it is not visible on an agarose gel. While RNeasy Kits will remove the vast majority of cellular DNA, trace amounts may still remain, depending on the amount and nature of the sample.
For analysis of very low abundance targets, any interference by residual DNA contamination can be detected by performing real-time RT-PCR control experiments in which no reverse transcriptase is added prior to the PCR step.
To prevent any interference by DNA in real-time RT-PCR applications, such as with
Applied Biosystems ® and Rotor-Gene
™ instruments, we recommend designing primers that anneal at intron splice junctions so that genomic DNA will not be amplified.
QuantiTect Primer Assays from QIAGEN are designed for SYBR ® Green-based real-time
RT-PCR analysis of RNA sequences (without detection of genomic DNA) where possible
(see www.qiagen.com/GeneGlobe). For real-time RT-PCR assays where amplification of genomic DNA cannot be avoided, we recommend using the QuantiTect Reverse
Transcription Kit for reverse transcription. The kit integrates fast cDNA synthesis with rapid removal of genomic DNA contamination (see ordering information, page 37).
†
* Wilfinger, W.W., Mackey, M., and Chomczynski, P. (1997) Effect of pH and ionic strength on the spectrophotometric assessment of nucleic acid purity. BioTechniques 22, 474.
Values up to 2.3 are routinely obtained for pure RNA (in 10 mM Tris·Cl, pH 7.5) with some spectrophotometers.
RNeasy Lipid Tissue Handbook 02/2009
31
1054915_HB 21.11.2008 9:08 Uhr Seite 32
For other sensitive applications, DNase digestion of the purified RNA with RNase-free
DNase is recommended. A protocol for optional on-column DNase digestion using the
RNase-Free DNase Set is provided in Appendix C (page 33). The DNase is efficiently washed away in subsequent wash steps.
Integrity of RNA
The integrity and size distribution of total RNA purified with RNeasy Lipid Tissue Kits can be checked by denaturing agarose gel electrophoresis and ethidium bromide staining* or by using the QIAxcel system or Agilent 2100 bioanalyzer. The respective ribosomal RNAs should appear as sharp bands or peaks. The apparent ratio of
28S rRNA to 18S rRNA should be approximately 2:1. If the ribosomal bands or peaks of a specific sample are not sharp, but appear as a smear towards smaller sized RNAs, it is likely that the sample suffered major degradation either before or during RNA purification.
The Agilent 2100 bioanalyzer also provides an RNA Integrity Number (RIN) as a useful measure of RNA integrity. Ideally, the RIN should be close to 10, but in many cases
(particularly with tissue samples), how well the original sample is preserved greatly influences RNA quality.
* When working with chemicals, always wear a suitable lab coat, disposable gloves, and protective goggles. For more information, consult the appropriate material safety data sheets (MSDSs), available from the product supplier.
32
RNeasy Lipid Tissue Handbook 02/2009
1054915_HB 21.11.2008 9:08 Uhr Seite 33
Appendix C: Optional On-Column DNase Digestion with the RNase-Free DNase Set
The RNase-Free DNase Set (cat. no. 79254) provides efficient on-column digestion of
DNA during RNA purification. The DNase is efficiently removed in subsequent wash steps.
Note: Standard DNase buffers are not compatible with on-column DNase digestion.
Use of other buffers may affect the binding of RNA to the RNeasy membrane, reducing
RNA yield and integrity.
Lysis and homogenization of the sample and binding of RNA to the RNeasy membrane are performed according to the standard protocol. After washing with a reduced volume of Buffer RW1, the RNA is treated with DNase I while bound to the RNeasy membrane. The DNase I is removed by a second wash with Buffer RW1. Washing with
Buffer RPE and elution of RNA are then performed according to the standard protocol.
Important points before starting
■
Generally, DNase digestion is not required since integrated QIAzol and RNeasy technologies efficiently remove most of the DNA without DNase treatment.
However, further DNA removal may be necessary for certain RNA applications that are sensitive to very small amounts of DNA (e.g., TaqMan RT-PCR analysis with a low-abundant target). DNA can also be removed by a DNase digestion following RNA purification.
■
Do not vortex the reconstituted DNase I. DNase I is especially sensitive to physical denaturation. Mixing should only be carried out by gently inverting the tube.
■
In the procedure below,
▲ refers to use of the RNeasy Lipid Tissue Mini Kit
, and
● refers to use of the RNeasy Lipid Tissue Midi Kit
.
Things to do before starting
■
Prepare DNase I stock solution before using the RNase-Free DNase Set for the first time. Dissolve the lyophilized DNase I (1500 Kunitz units) in 550 µl of the
RNase-free water provided. To avoid loss of DNase I, do not open the vial. Inject
RNase-free water into the vial using an RNase-free needle and syringe. Mix gently by inverting the vial. Do not vortex.
■
For long-term storage of DNase I, remove the stock solution from the glass vial, divide it into single-use aliquots, and store at –20°C for up to 9 months. Thawed aliquots can be stored at 2–8°C for up to 6 weeks. Do not refreeze the aliquots after thawing.
RNeasy Lipid Tissue Handbook 02/2009
33
1054915_HB 21.11.2008 9:08 Uhr Seite 34
Procedure
Prepare and load samples onto the RNeasy spin column as indicated in steps 1–10 of the protocol on page 14 or 19. Instead of performing step 11, follow steps C1–C4 below.
C1. Add
▲ 350 µl
or
● 2 ml
Buffer RW1 to the RNeasy spin column. Close the lid gently, and centrifuge for
▲ 15 s at ⱖ
8000 x g (
ⱖ
10,000 rpm) or
3000–5000 x g to wash the membrane. Discard the flow-through.*
● 5 min at
Reuse the collection tube in step C4.
C2. Add
▲ 10 µl
or
● 20 µl
DNase I stock solution (see above) to
▲ 70 µl
or
● 140 µl
Buffer RDD. Mix by gently inverting the tube, and centrifuge briefly to collect residual liquid from the sides of the tube.
Buffer RDD is supplied with the RNase-Free DNase Set.
Note: DNase I is especially sensitive to physical denaturation. Mixing should only be carried out by gently inverting the tube. Do not vortex.
C3. Add the DNase I incubation mix (
▲ 80 µl
or
● 160 µl
) directly to the RNeasy spin column membrane, and place on the benchtop (20–30°C) for 15 min.
Note: Be sure to add the DNase I incubation mix directly to the RNeasy spin column membrane. DNase digestion will be incomplete if part of the mix sticks to the walls or the O-ring of the spin column.
C4. Add
▲ 350 µl
or
● 2 ml
Buffer RW1 to the RNeasy spin column. Close the lid gently, and centrifuge for
▲ 15 s at ⱖ
8000 x g (
ⱖ
10,000 rpm) or
● 5 min at
3000–5000 x g . Discard the flow-through.* Continue with step 12 of the protocol on page 14 or 19.
* Flow-through contains Buffer RW1 and is therefore not compatible with bleach. See page 6 for safety information.
34
RNeasy Lipid Tissue Handbook 02/2009
1054915_HB 21.11.2008 9:08 Uhr Seite 35
Ordering Information
Product Contents
RNeasy Lipid Tissue
Mini Kit (50)
RNeasy Lipid Tissue
Midi Kit (10)
50 RNeasy Mini Spin Columns,
Collection Tubes, QIAzol Lysis
Reagent, RNase-Free Reagents and
Buffers
10 RNeasy Midi Spin Columns,
Collection Tubes, QIAzol Lysis
Reagent, RNase-Free Reagents and Buffers
Accessories
Allprotect Tissue Reagent
(100 ml)
RNA later RNA
Stabilization Reagent (50 ml)
For stabilization of DNA, RNA, and protein in 50 x 200 mg tissue samples: 100 ml Allprotect Tissue
Reagent, Allprotect Reagent Pump
For stabilization of RNA in
25 x 200 mg tissue samples:
50 ml RNA later RNA Stabilization
Reagent
RNA later RNA
For stabilization of RNA in
Stabilization Reagent (250 ml) 125 x 200 mg tissue samples:
250 ml RNA later RNA Stabilization
Reagent
RNA later TissueProtect
Tubes (50 x 1.5 ml)
For stabilization of RNA in
50 x 150 mg tissue samples:
50 screw-top tubes containing
1.5 ml RNA later RNA Stabilization
Reagent each
RNA later TissueProtect
Tubes (20 x 5 ml)
For stabilization of RNA in
20 x 500 mg tissue samples:
20 screw-top tubes containing
5 ml RNA later RNA Stabilization
Reagent each
QIAzol Lysis Reagent (200 ml) 200 ml QIAzol Lysis Reagent
Cat. no.
74804
75842
76405
76104
76106
76154
76163
79306
RNeasy Lipid Tissue Handbook 02/2009
35
1054915_HB 21.11.2008 9:08 Uhr Seite 36
Ordering Information
Product Contents Cat. no.
TissueRuptor
TissueRuptor
Disposable Probes (25)
TissueLyser II
TissueLyser Adapter
Set 2 x 24
Handheld rotor–stator homogenizer, 9001271*
5 TissueRuptor Disposable Probes 9001272 †
25 nonsterile plastic disposable probes for use with the TissueRuptor
9001273 ‡
9001274 §
990890
85300 Universal laboratory mixer-mill disruptor
2 sets of Adapter Plates and 2 racks for use with 2 ml microcentrifuge tubes on the TissueLyser
For dispensing individual beads
(5 mm diameter)
69982
69965 TissueLyser Single-Bead
Dispenser, 5 mm
Stainless Steel Beads,
5 mm (200)
RNase-Free DNase Set (50)
MaXtract High Density
(100 x 15 ml)
MaXtract High Density
(25 x 50 ml)
Collection Tubes (2 ml)
TissueLyser Adapter Set
2 x 96
Stainless Steel Beads, suitable for use with the TissueLyser system
For 50 RNA minipreps: 1500 units
RNase-Free DNase I, RNase-Free
Buffer RDD, and RNase-Free Water
100 x 15 ml MaXtract tubes for
100 nucleic acid extractions
25 x 50 ml MaXtract tubes for
25 nucleic acid extractions
1000 x 2 ml Collection Tubes
2 sets of Adapter Plates for use with
Collection Microtubes (racked) on the TissueLyser
Collection Microtubes (racked) Nonsterile polypropylene tubes
(1.2 ml), 960 in racks of 96
Collection Microtube Caps
(120 x 8)
Nonsterile polypropylene caps for collection microtubes (1.2 ml),
960 in strips of 8
69989
79254
129065
129073
19201
69984
19560
19566
§
‡
†
* 120 V, 60 Hz (for North America and Japan)
235 V, 50/60 Hz (for Europe, excluding UK and Ireland)
235 V, 50/60 Hz (for UK and Ireland)
235 V, 50/60 Hz (for Australia)
36
RNeasy Lipid Tissue Handbook 02/2009
1054915_HB 21.11.2008 9:08 Uhr Seite 37
Ordering Information
Product Contents
Related products
QuantiTect Reverse Transcription Kit — for fast cDNA synthesis for sensitive real-time two-step RT-PCR
QuantiTect Reverse
Transcription Kit (50)*
For 50 x 20 µl reactions: gDNA
Wipeout Buffer, Quantiscript ®
Reverse Transcriptase, Quantiscript
RT Buffer, RT Primer Mix, and
RNase-Free Water
RNeasy Kits — for purification of total RNA from animal cells or tissues, or yeast †
RNeasy Mini Kit (50) 50 RNeasy Mini Spin Columns,
Collection Tubes, RNase-Free
Reagents and Buffers
RNeasy Midi Kit (10) 10 RNeasy Midi Spin Columns,
Collection Tubes, RNase-Free
Reagents and Buffers
RNeasy Plus Mini Kit — for purification of total RNA from cultured cells and tissues using gDNA Eliminator columns
RNeasy Plus Mini Kit (50) 50 RNeasy Mini Spin Columns,
50 gDNA Eliminator Mini Spin
Columns, Collection Tubes,
RNase-Free Reagents and Buffers
RNeasy Fibrous Tissue Kits — for purification of total RNA from fiber-rich tissues
RNeasy Fibrous Tissue
Mini Kit (50)
RNeasy Fibrous Tissue
Midi Kit (10)
50 RNeasy Mini Spin Columns,
Collection Tubes, Proteinase K,
RNase-Free DNase I, RNase-Free
Reagents and Buffers
10 RNeasy Midi Spin Columns,
Collection Tubes, Proteinase K,
RNase-Free DNase I, RNase-Free
Reagents and Buffers
Cat. no.
205311
74104
75142
74134
74704
75742
†
* Larger kit size available; see www.qiagen.com/products/PCR.
Larger kit sizes and format available; see www.qiagen.com/RNA.
RNeasy Lipid Tissue Handbook 02/2009
37
1054915_HB 21.11.2008 9:08 Uhr Seite 38
Ordering Information
Product Contents Cat. no.
RNeasy 96 Universal Tissue Kit — for high-throughput RNA purification from any type of animal tissue
RNeasy 96 Universal
Tissue Kit (4) †‡
For 4 x 96 total RNA preps:
4 RNeasy 96 Plates, Collection
Microtubes, Elution Microtubes CL,
Caps, S-Blocks, AirPore Tape Sheets,
QIAzol Lysis Reagent, RNase-Free
Reagents and Buffers
miRNeasy Kits — for purification of microRNA and total RNA from a wide range of animal tissues and cells
miRNeasy Mini Kit (50) miRNeasy 96 Kit (4) ‡
74881
For 50 preps: 50 RNeasy Mini Spin 217004
Columns, Collection Tubes (1.5 ml and 2 ml), QIAzol Lysis Reagent,
RNase-Free Reagents and Buffers
217061 For 4 x 96 preps: 4 RNeasy
96 plates, Collection Microtubes
(racked), Elution Microtubes CL,
Caps, S-Blocks, AirPore Tape
Sheets, QIAzol Lysis Reagent,
RNase-Free Reagents and Buffers
Allprotect Tissue Reagent, RNA later RNA Stabilization Reagent, the TissueRuptor, the
TissueLyser II, and RNeasy Kits are intended for molecular biology applications. These products are neither intended for the diagnosis, prevention, or treatment of a disease, nor have they been validated for such use either alone or in combination with other products.
Visit www.qiagen.com/geneXpression to find out more about standardized solutions for gene expression analysis — from RNA preparation to real-time RT-PCR
†
‡
Larger kit size available; see www.qiagen.com/RNA.
Requires use of the QIAGEN 96-Well-Plate Centrifugation System with refrigeration capability (TissueLyser system recommended for disruption and homogenization; QIAvac 96 optional).
38
RNeasy Lipid Tissue Handbook 02/2009
1054915_HB 21.11.2008 9:08 Uhr Seite 39
Trademarks: QIAGEN
®
, QIAxcel
™
, QIAzol
®
, Quantiscript
®
, QuantiTect
®
, RNeasy
®
,
TissueRuptor
Biosystems
®
®
(QIAGEN Group); Agilent
®
(Agilent Technologies, Inc.); Applied
(Applera Corporation or its subsidiaries); Rotor-Gene
™
(Corbett Research);
SYBR
®
(Molecular Probes, Inc.); TaqMan
®
(Roche Group). “RNA later
®
” is a trademark of AMBION, Inc., Austin, Texas and is covered by various U.S. and foreign patents.
QIAzol Lysis Reagent is a subject of US Patent No. 5,346,994 and foreign equivalents.
Limited License Agreement
Use of this product signifies the agreement of any purchaser or user of the RNeasy Lipid Tissue Mini Kit or RNeasy Lipid Tissue Midi
Kit to the following terms:
1. The RNeasy Lipid Tissue Mini Kit or RNeasy Lipid Tissue Midi Kit may be used solely in accordance with the RNeasy Lipid
Tissue Handbook and for use with components contained in the Kit only. QIAGEN grants no license under any of its intellectual property to use or incorporate the enclosed components of this Kit with any components not included within this Kit except as described in the RNeasy Lipid Tissue Handbook and additional protocols available at www.qiagen.com.
2. Other than expressly stated licenses, QIAGEN makes no warranty that this Kit and/or its use(s) do not infringe the rights of third-parties.
3. This Kit and its components are licensed for one-time use and may not be reused, refurbished, or resold.
4. QIAGEN specifically disclaims any other licenses, expressed or implied other than those expressly stated.
5. The purchaser and user of the Kit agree not to take or permit anyone else to take any steps that could lead to or facilitate any acts prohibited above. QIAGEN may enforce the prohibitions of this Limited License Agreement in any Court, and shall recover all its investigative and Court costs, including attorney fees, in any action to enforce this Limited License Agreement or any of its intellectual property rights relating to the Kit and/or its components.
For updated license terms, see www.qiagen.com.
© 2002–2009 QIAGEN, all rights reserved.
1054915_HB 21.11.2008 9:08 Uhr Seite 40
www.qiagen.com
Australia
■
Orders 03-9840-9800
■
Fax 03-9840-9888
■
Technical 1-800-243-066
Austria
■
Orders 0800/28-10-10
■
Fax 0800/28-10-19
■
Technical 0800/28-10-11
Belgium
■
Orders 0800-79612
■
Fax 0800-79611
■
Technical 0800-79556
Brazil
■
Orders 0800-557779
■
Fax 55-11-5079-4001
■
Technical 0800-557779
Canada
■
Orders 800-572-9613
■
Fax 800-713-5951
■
Technical 800-DNA-PREP (800-362-7737)
China
■
Orders 0086-21-3865-3865
■
Fax 0086-21-3865-3965
■
Technical 800-988-0325, 800-988-0327
Denmark
■
Orders 80-885945
■
Fax 80-885944
■
Technical 80-885942
Finland
■
Orders 0800-914416
■
Fax 0800-914415
■
Technical 0800-914413
France
■
Orders 01-60-920-926
■
Fax 01-60-920-925
■
Technical 01-60-920-930
■
Offers 01-60-920-928
Germany
■
Orders 02103-29-12000
■
Fax 02103-29-22000
■
Technical 02103-29-12400
Hong Kong
■
Orders 800 933 965
■
Fax 800 930 439
■
Technical 800 930 425
Ireland
■
Orders 1800-555-049
■
Fax 1800-555-048
■
Technical 1800-555-061
Italy
■
Orders 02-33430-420
■
Fax 02-33430-426
■
Technical 800-787980
Japan
■
Telephone 03-6890-7300
■
Fax 03-5547-0818
■
Technical 03-6890-7300
Korea (South)
■
Orders 1544 7145
■
Fax 1544 7146
■
Technical 1544 7145
Luxembourg
■
Orders 8002-2076
■
Fax 8002-2073
■
Technical 8002-2067
Mexico
■
Orders 01-800-7742-639
■
Fax 01-800-1122-330
■
Technical 01-800-7742-639
The Netherlands
■
Orders 0800-0229592
■
Fax 0800-0229593
■
Technical 0800-0229602
Norway
■
Orders 800-18859
■
Fax 800-18817
■
Technical 800-18712
Singapore
■
Orders 65-67775366
■
Fax 65-67785177
■
Technical 65-67775366
Spain
■
Orders 91-630-7050
■
Fax 91-630-5145
■
Technical 91-630-7050
Sweden
■
Orders 020-790282
■
Fax 020-790582
■
Technical 020-798328
Switzerland
■
Orders 055-254-22-11
■
Fax 055-254-22-13
■
Technical 055-254-22-12
UK
■
Orders 01293-422-911
■
Fax 01293-422-922
■
Technical 01293-422-999
USA
■
Orders 800-426-8157
■
Fax 800-718-2056
■
Technical 800-DNA-PREP (800-362-7737)
1054915 02/2009
Sample & Assay Technologies
1054915_Tear-Out 17.11.2008 10:55 Uhr Seite 1
BenchProtocol
RNA Purification Using RNeasy Lipid Tissue Mini Kit
Note: Before using this bench protocol, you should be completely familiar with the safety information and protocols in the RNeasy Lipid Tissue Handbook.
Procedure
1.
Disrupt and homogenize
ⱕ
100 mg fatty tissue (
ⱕ
50 mg other tissue) in 1 ml
QIAzol Lysis Reagent using the TissueRuptor or TissueLyser.
2.
Incubate sample at room temperature for 5 min.
3.
Add 200 µl chloroform, and shake vigorously for 15 s.
4.
Incubate sample at room temperature for 2–3 min.
5.
Centrifuge at 12,000 x g for 15 min at 4°C.
6.
Transfer upper, aqueous phase to new tube, add 1 volume of 70% ethanol, and vortex. Do not centrifuge. Proceed at once to step 7.
7.
Transfer sample to RNeasy column in 2 ml tube. Close lid, centrifuge for 15 s at
ⱖ
8000 x g, and discard flow-through.
Optional DNase digest: Follow steps 1–4 of “Bench Protocol: Optional
On-Column DNase Digestion for RNeasy Lipid Tissue Mini Kit” after this step.
8.
Add 700 µl Buffer RW1 to RNeasy column. Close lid, centrifuge for 15 s at
ⱖ
8000 x g, and discard flow-through.
Skip this step if performing optional DNase digestion.
9.
Add 500 µl Buffer RPE to RNeasy column. Close lid, centrifuge for 15 s at
ⱖ
8000 x g, and discard flow-through.
10. Add 500 µl Buffer RPE to RNeasy column. Close lid and centrifuge for 2 min at
ⱖ
8000 x g.
11. Optional: Place RNeasy column in new 2 ml tube, close lid, and centrifuge at full speed for 1 min.
12. Place RNeasy column in new 1.5 ml tube. Add 30–50 µl RNase-free water, close lid, and centrifuge for 1 min at
ⱖ
8000 x g.
Optional: Repeat elution with another volume of water or with RNA eluate.
Sample & Assay Technologies
1054915_Tear-Out 17.11.2008 10:55 Uhr Seite 2
BenchProtocol
Optional On-Column DNase Digestion for RNeasy
Lipid Tissue Mini Kit
Note: Before using this bench protocol, you should be completely familiar with the safety information and detailed protocols in the RNeasy Lipid Tissue Handbook.
Things to do before starting
If using the RNase-Free DNase Set for the first time, prepare DNase I stock solution. Using an RNase-free needle and syringe, inject 550 µl RNase-free water into the DNase I vial (1500 Kunitz units). Mix gently by inverting the vial.
Do not vortex.
For long-term storage of DNase I stock solution, divide it into single-use aliquots and store at –20°C for up to 9 months. Thawed aliquots can be stored at 2–8°C for up to 6 weeks. Do not refreeze aliquots after thawing.
Procedure
Perform steps 1–7 of “Bench Protocol: RNA Purification Using the RNeasy Lipid Tissue Mini Kit”. Then perform steps 1–4 below.
1.
Add 350 µl Buffer RW1 to RNeasy column, close lid, centrifuge for 15 s at
ⱖ
8000 x g, and discard flow-through.
2.
Add 10 µl DNase I stock solution (see above) to 70 µl Buffer RDD. Mix by gently inverting tube, and centrifuge briefly.
3.
Add DNase I incubation mix (80 µl) directly to RNeasy column membrane, and place on benchtop (20–30°C) for 15 min.
4.
Add 350 µl Buffer RW1 to RNeasy column, close lid, centrifuge for 15 s at
ⱖ
8000 x g, and discard flow-through. Continue with step 9 of “Bench Protocol:
RNA Purification Using the RNeasy Lipid Tissue Mini Kit”.
Sample & Assay Technologies
1054915_Tear-Out 17.11.2008 10:55 Uhr Seite 3
BenchProtocol
RNA Purification Using RNeasy Lipid Tissue Midi Kit
Note: Before using this bench protocol, you should be completely familiar with the safety information and protocols in the RNeasy Lipid Tissue Handbook.
Procedure
1.
Disrupt and homogenize
ⱕ
500 mg fatty tissue (
ⱕ
250 mg other tissue) in 5 ml
QIAzol Lysis Reagent using the TissueRuptor.
2.
Incubate sample at room temperature for 5 min.
3.
Add 1 ml chloroform, and shake vigorously for 15 s.
4.
Incubate sample at room temperature for 2–3 min.
5.
Centrifuge at 5000 x g for 15 min at 4°C.
6.
Transfer upper, aqueous phase to new tube, add 1 volume of 70% ethanol, and vortex. Do not centrifuge. Proceed at once to step 7.
7.
Transfer sample to RNeasy column in 15 ml tube. Close lid, centrifuge for 5 min at 3000–5000 x g, and discard flow-through.
Optional DNase digest: Follow steps 1–4 of “Bench Protocol: Optional
On-Column DNase Digestion for RNeasy Lipid Tissue Midi Kit” after this step.
8.
Add 4 ml Buffer RW1 to RNeasy column. Close lid, centrifuge for 5 min at
3000–5000 x g, and discard flow-through.
Skip this step if performing optional DNase digestion.
9.
Add 2.5 ml Buffer RPE to RNeasy column. Close lid, centrifuge for 2 min at
3000–5000 x g, and discard flow-through.
10. Add 2.5 ml Buffer RPE to RNeasy column. Close lid and centrifuge for 5 min at
3000–5000 x g.
11. Place RNeasy column in new 15 ml tube. Add RNase-free water (150 µl if expecting
ⱕ
150 µg RNA, or 250 µl if expecting
ⱕ
1 mg RNA), close lid, wait
1 min, and centrifuge for 3 min at 3000–5000 x g.
Optional: Repeat elution with another volume of water or with RNA eluate.
Sample & Assay Technologies
1054915_Tear-Out 17.11.2008 10:55 Uhr Seite 4
BenchProtocol
Optional On-Column DNase Digestion for RNeasy
Lipid Tissue Midi Kit
Note: Before using this bench protocol, you should be completely familiar with the safety information and detailed protocols in the RNeasy Lipid Tissue Handbook.
Things to do before starting
If using the RNase-Free DNase Set for the first time, prepare DNase I stock solution. Using an RNase-free needle and syringe, inject 550 µl RNase-free water into the DNase I vial (1500 Kunitz units). Mix gently by inverting the vial.
Do not vortex.
For long-term storage of DNase I stock solution, divide it into single-use aliquots and store at –20°C for up to 9 months. Thawed aliquots can be stored at 2–8°C for up to 6 weeks. Do not refreeze aliquots after thawing.
Procedure
Perform steps 1–7 of “Bench Protocol: RNA Purification Using the RNeasy Lipid Tissue Midi Kit”. Then perform steps 1–4 below.
1.
Add 2 ml Buffer RW1 to RNeasy column, close lid, centrifuge for 5 min at
3000–5000 x g, and discard flow-through.
2.
Add 20 µl DNase I stock solution (see above) to 140 µl Buffer RDD. Mix by gently inverting tube, and centrifuge briefly.
3.
Add DNase I incubation mix (160 µl) directly to RNeasy column membrane, and place on benchtop (20–30°C) for 15 min.
4.
Add 2 ml Buffer RW1 to RNeasy column, close lid, centrifuge for 5 min at
3000–5000 x g, and discard flow-through. Continue with step 9 of “Bench
Protocol: RNA Purification Using the RNeasy Lipid Tissue Midi Kit”.
Sample & Assay Technologies

Public link updated
The public link to your chat has been updated.
Advertisement
Key features
- Efficient lysis of fatty tissues
- Purification of high-quality total RNA
- Compatible with all animal tissues
- Includes QIAzol Lysis Reagent for RNase inhibition
- RNeasy spin columns for RNA binding and purification
- Optional on-column DNase digestion
- High RNA yields and purity