Circular Dichroism Spectrometer

photo of Circular Dichroism Spectrometer

Location: Level 1 South, Room 115

Model: Aviv Biomedical Model 410 with stopped flow unit add-on

Circular dichroism (CD) spectrometry measures the extent of secondary structure in a protein and is based on the differential absorption of left and right circularly polarised light.

The technique is exquisitely sensitive to protein structural changes and is well suited to the assessment of conformational stability and/or the effects of amino acid substitutions.

It is also highly useful for looking at kinetics of changes in response to temperature or additives to the buffer solvent.

The MIF Aviv instrument is capable of measuring a wavelength range of 160 nm to 850 nm, with temperature control from 4 ºC to 100 ºC. It also has an add-on unit for performing stopped-flow experiments for measuring structural changes in the millisecond timescale.


For excellent notes on sample preparation and appropriate buffers to use, see the Vanderbilt University’s Center for Structural Biology CD page.

Experimental data from the spectrometer can be analysed in terms of the extent of secondary structure (random coil, alpha-helix, beta-strand) using either the online Dichroweb service (registration required) or an MS-DOS program, CD Pro.