Circular Dichroism Spectrophotometers

Whether you are doing protein denaturation studies 260-190 nm or MCD 1100-2700 nm, you want the right answer. And you want it quickly, easily, perfectly.

Design advances by OLIS make these instruments as easy to use correctly as a UV/Vis spectrometer. After all: CD is abs(L) minus abs(R).

These advances simplify all instrument settings and eliminate all potential for incorrect answers.

The right answer is the only answer an OLIS CD can return.

Non-OLIS CDs

calculate the answer as

decoupled AC and DC intensities,

times a calibration constant k,

i.e., k[(IAC/IDC)]”

Should you care? Yes! if you want to eliminate as many routes to problems as possible. Yes! If you want the peace of mind that comes from knowing that the answer can only be correct. Yes! If you want best results with least waste.

Did you notice another attribute of the OLIS CDs? They utilize all of the light, collecting and averaging two CD scans simultaneously.

All OLIS DSM CDs

collect the answer as

CD = abs(L) - abs(R)

The “DSM” moniker was coined in the 1990s when the software was written which eliminated the need for the 1960s era lock-in amplifier that all other CD manufacturers continue to rely on.

Our brilliantbreakthroughs can lead to yours! Read More.

  • OLIS Upcycled 8452 UV/Vis

    CD and absorbance 185-1700 nm;
    extendible to 2600 nm

    CPL, fluorescence, and anisotropy, 230-870 nm

    Polarization Toolbox sample compartment
    for tool-free positioning of polarizers and PEM

    LED source provided for select CPL excitation

    Prism-grating CARY monochromator with all the outstanding performance characteristics of the original classic

  • OLIS DSM 1000 CD UV/Vis

    Highest sensitivity DSM CD

    167-540 nm

    Exclusive OLIS RSM 1000 monochromator

    Optional millisecond spectral scanning during ABS (not CD)

  • DSM 17 CD UV/Vis/NIR

    Full scanning range of 185-1700 nm, optionally extended to 2600 nm

    Useful for nearly all CD studies, including MCD

    Prism-grating CARY monochromator with
    all the outstanding

    performance characteristics of the original classic.

  • OLIS DSM 172 UV/Vis/NIR

    CD and absorbance 185-1700 nm;
    extendible to 2600 nm

    CPL, fluorescence, and anisotropy, 230-870 nm

    Polarization Toolbox sample compartment
    for tool-free positioning of polarizers and PEM

    LED source provided for select CPL excitation

    Prism-grating CARY monochromator with all the outstanding performance characteristics of the original classic

  • OLIS DSM 245

    CD and absorbance 170-700 nm;

    CPL, fluorescence and anisotropy 230 - 870 nm

    Physically small with two OLIS monochromators, including the subtractive double grating OLIS Hummingbird

    Polarization Toolbox sample compartment

    for tool-free positioning of polarizers and PEM

    LED source provided for select CPL excitation

  • Phosphorescence Lifetime PLT3

    Direct alternative to time correlated single photon counting

    Fast & flexible...collect a decay curve up to 4,000 times per second

    You can purchase this as a free-standing system or purchase the hardware/ software for seamless integration of phosphorescence lifetime into a OLIS spectrophotometer, where the sample compartment and computerization come from the host instrument.

Practical Considerations when comparing “170 nm” (OLIS) with “163 nm” (APP and Jasco):

Our competition in the UK, Applied Photophysics, has produced a nice document reminding everyone that “170 nm is the lower wavelength limit for benchtop CD instruments, and is only achievable with experimental conditions that are not really feasible for every-day work.”

The document ends with  “As with other technical specifications, comparisons of different instruments against each other should be based on sensible, applicable requirements rather than numbers that lack relation to real-life situations.

Unfortunately, a technical specification sheet is not designed to include comprehensive and intricate considerations such as those above. Fortunately, though, there are avid users such as yourself who take the time to learn and understand them!”

Read the full document here:

How low can we go? (photophysics.com)

Resources

Linearity of the OLIS DSM CDs

Numerous advantages come from the direct subtractive method (DSM) which was pioneered by Dr. Richard J. DeSa in the 1990s and made possible by the brilliant software developed by Denghui Cheng, including perfect linearity as far as you will ever need.