MOS-500 - Bio

CD-LAB PRODUCTS
SPECTROPOLARIMETER
MOS-500 Spectrometer
Circular Dichroism
Everything you expect from a spectropolarimeter
peed and sensitivity
S
Stability
Modularity
Low running cost
User-friendliness
MOS-500 uses an innovative and patented
three stage wavelength selection system to
bypass the limitation of traditional prismbased monochromators.
The design delivers outstanding performance in
wavelength range, sensitivity, precision, speed, and
modularity.
Operating cost is reduced as well, since the MOS-500
requires purging of optics only when working
below 195 nm. A standard dual lamp box adds
to the convenience of the system, and an optional
tungsten lamp enhances IR performance.
Thanks to its modular design the MOS-500
is much more than a CD spectrophotometer.
Multiple detection modes and a wide range
of accessories from stopped-flow to
ORD are available to allow you to
adapt the system to
your research.
GENERAL SPECIFICATIONS
163-950 nm, and 0 nm (white light)
(up to 1,250 nm optional)
Dual light source ( Xe and XeHg)
±0.1 nm wavelength accuracy over full wavelength range
Peltier temperature control optional
Unsurpassed baseline stability
Fast and sensitive
Standard detection modes: CD/Absorbance/HV,
Fluorescence, FD/CD, Fluorescence anisotropy and polarization, LD, HPLC-CD
Optional modes: NIR-CD, ORD, DR-CD,
Stopped-flow and titration, Emission fluorescence
Innovation and performance
40
30
25
30
20
15
MilliDegree
MilliDegree
20
10
0
5
0
-5
-10
-20
10
-10
200 220 240 260 280 300 320 340
Wavelength (nm)
0.06% Camphor sulfonic acid 0.2 s/pt, 0.25 nm steps, and
1 nm bandwidth
-15
180
190
200 210 220 230
Wavelength (nm)
240
250
CD spectra collected with 0.5 s/pt, 0.25 nm steps, and 1 nm bandwidth
lysozyme (green), cytochrome c (red) and myoglobine (blue)
Unsurpassed stability
Multiple scanning modes
The combination of super quiet light source with ultra
stable optics and electronics make the MOS-500
the most stable spectropolarimeter on the market by
a full order of magnitude.
Scanning speed can be set by the user, or
automatically controlled in software to optimize the
quality of spectral data. Under software control the
scanning speed is reduced for wavelengths where
the level of light is low. The user can display raw
data or apply post acquisition processing. Scans can
be easily synchronized with temperature or titration
steps through Biokine software.
It is ideal for measurements and titrations that take
hours to complete.
Low noise
Double light source
The optical components and design were carefully
chosen for the best quality, longevity, and efficiency.
The optical path is optimized so the maximum
amount of light reaches the detector from far UV to
NIR. The photomultiplier detector was chosen to offer
the highest sensitivity from far UV to 950 nm. The
wide range detector means the system can be used
for no compromise fluorescence measurements,
making MOS-500 a more versatile and cost effective
instrument. Optional PMTs can be installed for
specific applications if needed, without upgrading
hardware.
The MOS-500 includes a Xenon/Xenon (Hg) double
light source. The xenon lamp is preferred for UV-Vis
scans and XeHg for single wavelength applications.
MOS-500, SPECTROPOLARIMETER
The user can select either source in seconds
without handling or re-aligning the lamp. This
makes the system especially valuable in a multiuser lab.
The MOS-500 can accommodate lamps from 75 W
to 200 W, and tungsten lamps are available for
different application needs.
3
Unique Technology
10
+/- nm
1
0.1
0.01
100
300
500
700
Wavelength (nm)
900
1100
Wavelength accuracy profile for MOS-500
prism based spectrometers
Tunable chromatic
light source Coupled
to a double grating
monochromator
The MOS-500 combines a patented chromatic
illumination system with a new grating design to
provide wavelength range, diffraction efficiency, and
accuracy.
The patented chromatic illumination system provides
the initial selection of the wavelength. Like a prism
monochromator it uses the variation of the refractive
index of quartz. This is followed by the latest design
double grating monochromator to give constant and
optimal resolution, and precision at all wavelengths.
The chromatic illumination of the double
monochromator also reduces the energy received by
the monochromator and extend lifetime of the optics.
Monochromators are confined so level of stray light is
minimum, allowing high performance spectra in the
far-UV. The slit mechanism is software controlled,
and bandwidth can be selected freely from 0 to 16 nm.
The MOS-500 also includes a software controlled
shutter for photosensitive samples.
Grating vs Prism
Conventional CD spectrometers based on double
prism monochromators use prisms to polarize light.
Prisms provide good wavelength resolution in UV
region, but in the visible and IR region however,
wavelength precision can be reduced by a factor of 20.
Precision is also reduced when compared to gratings
in the same wavelength ranges. This makes it difficult
to run well resolved spectra using small slits.
In addition, prism monochromators are not ideal for
rapid kinetics studies even in UV region. Indeed for
kinetics user wants to get as much light as possible
and often wishes to open slits widely which is not
always possible with prism monochromators.
The MOS-500 combination of a tunable chromatic
light source with gratings offers the best
performance over the full UV, visible and NIR range.
Instead of choosing between
prism and grating monochromator
the MOS-500 combines the
best of both worlds
Low running cost - save more than 5,000 e a year
Calculation is based on a daily use at a 3l/ min N2 flushing of optics
(recommended by other manufacturers) and cost of one N2 bottle in 2012.
Instrument being used above 200 nm only.
1200
PMT high voltage (V)
1000
800
600
400
200
175
180
185
190
195
Wavelength (nm)
200
205
210
HV spectra with and without N2 flushing (no effect above 195 nm)
No need for N2 flushing
above 195 nm
Classical CD instrument manufacturers have made
nitrogen flushing a requirement for CD
measurements. The main reason is the need to
remove oxygen and to reduce its light absorption in
the far-UV range. This is important for wavelength
shorter than 195 nm, but N2 flushing is useless from
195 nm to NIR. Another reason is the need to protect
refective coatings from ozone generated by UV
reaction with oxygen in the lamp compartment.
Automatic variable
focalization
The MOS-500 design dramatically reduces the need
for N2 flushing. It is designed without focusing
mirrors in the lamp compartment, so there is no risk
to the optics. The gas purge space is divided into
three areas: the light source, the optical bench and
the sample compartment.
The sample compartment is large and accessible to
accommodate many options. The focal point is
automatically adjusted to accommodate the detection
mode and accessory installed.
The instrument is sealed so the N2 purge can be
stopped in the lamp housing and optical bench after
20 minutes of operation, while keeping outstanding
performances in the far UV range.
The light beam can be parallel, or be focused on the
cell, or on the detector to offer the best signal to
noise for each experimental condition. The detector
position can also be as close as possible to the cell.
These automatic adjustments are unique and a key to
delivering the best performance in the most
demanding applications.
MOS-500, SPECTROPOLARIMETER
5
More than just a CD Spectrometer
0.21
0.125
0.18
0.15
0.12
Anisotropy
Anisotropy
0.12
0.09
0.06
0.03
0.115
0.11
0
-0.03
240
0.105
250
260 270 280
Wavelength (nm)
290
300
Lysozyme fluorescence anisotropy spectrum
10
20
30
40 50
Time (s)
60
70
BSA/Phloxine reaction followed
in anisotropy mode
Polarization and
Fluorescence Anisotropy
The MOS-500 includes a unique fluorescence
anisotropy measurement mode. The EMFA® method
uses fast modulation of the polarized excitation light
and synchronous detection of the fluorescence signal
to achieve a very sensitive and fast measurement of
sample anisotropy.
Fluorescence and FD-CD
The standard photomultiplier tube covers a
wavelength range from 160 nm to 950 nm. It is ideal
for fluorescence application. The PMT housing can be
easily relocated at 90° to the beam for fluorescence
or FD-CD measurements. The PMT housing accepts 1
inch diameter filters to select emission light.
Fluorescence anisotropy is a useful technique in a
wide range of application: binding, denaturation,
aggregation and crystallization, or any reaction
inducing a total or a partial change of flexibility of the
molecule holding the chromophore.
When doing Fluorescence Detected Circular
Dichroism (FD-CD), the photo elastic modulator
alternatively generates left and right circularly
polarized light. The difference between the two
polarization signals is measured with the PMT
installed at 90° to the beam.
Data can be displayed in anisotropy units, or as the
two polarized signals. Total Fluorescence is also
measured simultaneously.
If the user wants to simultaneously record CD and
fluorescence signals, or dual fluorescence, second
PMT is required.
Excitation Modulated
Fluorescence Anisotropy
EMFA method was developed and patented
by Bio-logic in 1999.
Refer to World Intellectual Property Organization
website for details.
A multi-channel approach
0
-0.002
The MOS-500 was designed to provide a multi-modal
approach. CD, absorbance and HV can be recorded
simultaneously, and the user can add temperature
and fluorescence signals with additional accessories.
When temperature is controlled through a Peltier
element, dynamic multimode spectroscopy
measurements are possible.
LD (delta A)
-0.004
-0.006
-0.008
-0.01
-0.012
-0.014
-0.016
200
220
240
260
Wavelength (nm)
280
300
The MOS-500 is by far the most modular and highest
performing system on the market, with outstanding
specifications in every detection modes.
28 µg/ml DNA spectra using 1 second sampling
Linear dichroism
HPLC-CD
Linear dichroism is the difference in absorption of
parallel and perpendicular linearly polarized light.
These two polarizations are generated by using half
wave retardation with a photo elastic modulator. LD
gives information on the orientation of biomacromolecule.
The MOS-500 can be coupled to HPLC instruments
using a commercial flow cell fitted into the sample
compartment. Biokine software can be triggered from
the HPLC to record the chromatogram. The CD signal
can also be fed back into the HPLC for data
comparison and analysis.
The HPLC-CD signal can be recorded over the full
wavelength range of the MOS-500.
The MOS-500 includes hardware and software to
measure LD signals in steady state and kinetics
mode. To collect LD spectra the user can use
commercial flow through cells or an optional couette
cell to orient the sample in the cell.
MOS-500, SPECTROPOLARIMETER
7
55
15
50
10
45
5
40
0
MilliDegree
Degree (°C)
Temperature Control
35
30
-10
-15
25
20
-5
-20
200
400
600 800
Time (s)
1000 1200 1400
Precision of sample temperature
recording without overshoot
(10°C, 5°C and 1°C temperature steps)
200
210
220
Wavelength (nm)
230
240
Thermal denaturation of lysozyme
(from 30°C to 85°C in a 1 cm cuvette)
Single cell Peltier
Temperature controller
Multi-cell Peltier
Temperature controller
The MOS-500 can be equipped with an optional
Peltier temperature controller for precise and rapid
temperature control of the cell. The temperature of
the Peltier element is regulated according to the real
temperature of the cell for smooth control without
overshoot. The measured temperature corresponds
exactly to the target temperature without any gradient
due to the distance between the Peltier and the cell.
The MOS-500 can be fitted with a 4-cell Peltier
temperature controller for precise temperature
regulation of up to four samples. Each cell has its own
magnetic stirrer. The operating range is -40°C to
105°C using a circulating chiller unit.
Temperature ramping is easily programmable from
Biokine software. At each temperature step a CD
spectrum can be measured automatically. For single
wavelength thermal stability studies it is also possible
to directly measure the CD signal versus temperature
to determine thermodynamic properties of a protein
(Tm, ΔCp, ΔS).
Specifications
Full software control
0.01°C precision
Magnetic stirring standard
Temperature range: -10°C to 110°C
Temperature of the cell and Peltier can both be
measured
Easy programming
The Multi-cell temperature controller is fully
controlled from Biokine software, including cell
position in the beam, temperature ramping, or single
temperature scans. NIR upgrade
550
500
The NIR option extends wavelength range to 1,250 nm. It includes a
photomultiplier tube optimized for NIR range, and a tungsten lamp.
A tungsten lamp adds to the better performance, since tungsten bulbs do
not have sharp intensity peaks which makes lamp regulation difficult.
400
Volt
Conventional CD spectrometers based on prism monochromators are
optimized to separate light in the far UV. However, the longer the
wavelength, the worse the wavelength resolution, and it is impossible to
work with small slits and to detect narrow CD peaks. Bio-Logic’s new
wavelength focusing system with grating monochromators gives the user
the same wavelength resolution over the full wavelength range. In the NIR
region the MOS-500 offers 20 times better accuracy compared to a prism
based system.
450
350
300
250
200
150
800
900
1000
Wavelength (nm)
1100
1200
Comparative HV spectra of Xenon and Tungsten lamp
in NIR region (xenon peaks are clearly observed)
Intuitive software
The MOS-500 and all accessories are fully controlled
from Biokine software. Acquisition parameters are
selected from a single window for easy experiment
design. Data files can be saved in different formats for
internal analysis, or easily exported to secondary
structure analysis software for example.
MOS-500, SPECTROPOLARIMETER
9
Options
300
0
-10
100
MilliDegree
MilliDegree
200
0
-100
-200
-20
-30
-40
-300
220 240 260 280 300 320 340 360
Wavelength (nm)
CD and ORD spectra of camphor sulfonic acid
showing positive cotton effects
220
240
260 280 300
Wavelength (nm)
320
340
360
DR-CD spectra of camphor sulfonic acid
ORD accessory
DR-CD: CD-powder
ORD (Optical Rotary Dispersion) and CD are closely
related techniques. ORD is used to study the chirality
of a biomolecule by passing a beam of linearly
polarized light through the sample. If the sample is
chiral, then the light will be rotated as a function of
wavelength. From this rotation, the user can
determine the left- or right-handed chirality of the
molecule. No physical rotation of the polarizer is
required during acquisition so an ORD spectrum can
be collected over tens of seconds with a outstanding
sensitivity. The ORD accessory is mounted on a
standard photomultiplier tube. It includes one
polarizer and a special PMT holder equipped with a
micrometric screw, allowing fine adjustment of the
polarizer position before measurements. Electronics
in the MOS-500 do not need to be upgraded when
adding the ORD accessory.
Measuring CD spectra on powder has long been
desired as a way to eliminate solvent contribution. A
Pellet technique can be used, but the quality of results
is very dependent upon quality of sample preparation.
The ORD accessory can also be used for steady state
measurements.
Specifications
2
10-900 nm (1,200 nm when combined with IR
accessory)
±10 degrees
Detection limit: 0.01 mdeg
Bio-Logic has designed a Diffuse Reflectance CD
accessory based on an integration sphere using an
internal coating specially chosen for its high
reflectance. The DR-CD accessory can be installed in
seconds in the sample compartment. The powder
holder is designed to minimize linear dichroism
artifacts, and is installed directly into the integration
sphere.
High quality spectra can be obtained in minutes on
solid samples like powders and other samples like
leaves.
Specifications
2
00-900 nm (1,200 nm when combined with IR
accessory)
MilliDegree
18
16
14
12
10
8
6
4
2
0
0
Circular dichroism
0.2
0.4
0.6
Time (s)
0.8
1
3.8
3.6
3.4
Volt
3.2
3
2.8
2.6
2.4
All stopped-flow mixing systems manufactured by Bio-logic can be attached to
the MOS-500 in minutes. The latest generation SFM-2000/3000/4000 mixers
deliver outstanding kinetics specification. Our SFM models are based on
independent stepping motor technology and Berger Ball mixers which provide
the best kinetics performance on the market. A series of experiments such as
concentration dependence studies can be done quickly and automatically, without
changing syringes or doing manual dilution. This saves time for the user.
1
1.2
1.4
0.06
0.04
0.02
0
Absorbance
0
0.002 0.004 0.006 0.008 0.01 0.012 0.014 0.016
Time (s)
0.09
0.08
LD (delta A)
0.07
0.06
0.05
0.04
0.03
0.02
0.01
Linear dichroism
MOS-500, SPECTROPOLARIMETER
0.6 0.8
Time (s)
0.08
Specifications
0.2 ms dead time (with optional microcuvette)
M
ixing ratio fully controllable form 1:1 to 1:100
Single, double, and triple mixing
A
utomatic concentration dependence studies
Choice of 10 cuvettes
Low sample volume requirement
For absorbance, fluorescence, CD, anisotropy,
LD, chemiluminescence, 90° light scattering
0.4
0.1
Stopped-flow kinetics can be measured in all detection modes. A dead time of
0.2 ms can be obtained in all detection modes with the optional micro-cuvette.
Nitrogen flushing of optics is not necessary when the MOS-500 is operated in
stopped-flow configuration. To get an optimum signal to noise ratio in
kinetics mode it could be essential to use a XeHg lamp (222 nm alpha
helix, Trp fluorescence…). The dual light source of MOS-500 allows switching
from Xe to XeHg lamp in seconds without handling or realigning the bulb. It is the
easiest to use lamp system available.
0.2
0.12
AU
Stopped-Flow
0
Fluorescence
0
0.1
0.2
0.3
Time (s)
0.4
0.5
11
0.6
Specifications
SPECIFICATIONS
Light source
super quiet 150 W Xe and Xe (Hg) air-cooled,
tungsten available in option (air-cooled)
Monochromator
tunable chromatic light source coupled to double grating (patented)
Wavelength range
163-950 nm (standard),
163-1250 nm (with optional detector)
Nitrogen gas purge
only for scans < 195 nm ( no risk of damaging optics),
high efficiency N2 purge optimized for light source,
optical bench and sample compartment
Wavelength accuracy
±0.1 nm from 163 to 1,250 nm
Wavelength precision
±0.05 nm from 163 to 1,250 nm
Bandwidth
0 to 16 nm on full wavelength range
Stray light
< 2 ppm at 200 nm
CD resolution
0.00001 mdeg
CD range*
±7,500 mdeg
Baseline stability
±0.007 mdeg/hour
Scanning speed
0.1 ms to 20 s per data point
Data interval
0.1 nm to 10 nm in scanning mode,
10 µs to 20 s in kinetics mode
Scanning modes
step scan,
adaptive scan,
temperature scan,
kinetics (slow or using stopped-flow)
Rms noise**
0.015 mdeg at 185 nm using 1 nm BW, 16 s sampling
0.01 mdeg at 200 nm using 1 nm BW, 16 s sampling
0.007 mdeg at 500 nm using 1 nm BW, 16 s sampling
Standard detection modes
CD, Absorbance, HV (standard all simultaneous)
Fluorescence, FD/CD, Fluorescence anisotropy, HPLC-CD, LD
Optional detection mode
NIR-CD, ORD, DR-CD
UV measurement
accuracy ±0.001 AU (built-in filters to remove second order)
Shutter
built-in, software control
External input/output
4 in, 3 out (for external connections)
PC interface
Windows 7, 32 or 64 bits
Other options
titrator (concentration and pH), emission monochromator
Dimensions
139 x 32 x 39 (cm, W x D x H)
Weight
35 kg
Specifications are subject to change
*Typical value. Customization to higher values is possible, please contact your local distributor.
**Wavelength enhanced customization available, please contact your local distributor.
Headquarters
Bio-Logic SAS
1, rue de l’Europe
38 640 Claix - France
Phone: +33 476 98 68 31
Fax: +33 476 98 69 09
www.bio-logic.info
Affiliate offices
Bio-Logic USA, LLC
P.O.Box 30009 - Knoxville, TN37930 - USA
Phone: +1 865 769 3800 - Fax: +1 865 769 3801
Bio-Logic Science Instruments Pvt Ltd
304,Orion Business Park, Next to Cine Wonder,
G. B. Road, Thane(W), 400 607 Mumbai - India
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