Jasco J-1500 Circular Dichroism Spectrometer

Circular dichroism (CD) measures the difference in absorbance of left- and right- handed polarized light of chiral molecules.  CD is commonly used to analyse the conformation of macromolecules, particularly protein secondary structure.

Linear dichroism (LD) measures the difference in absorption of light linearly polarised parallel and perpendicular to the orientation axis. LD can be used to give information about the conformation and orientation of structures with molecules that are either intrinsically oriented, or can be oriented during an experiment by external forces such as DNA complexes, fibrous proteins such as (e.g. cytoskeleton and amyloid proteins) and membrane peptides/proteins in liposomes.

The J-1500 is a hybrid instrument consisting of a variable wavelength polarimeter for CD or LD and absorption spectrophotometer (~180-900 nm, Far-UV to Vis range). The J-1500 is fitted with a 6-position multi-cell changer and computer controlled Peltier cooling/heating system. This set-up is ideally suited to:

• Determine protein secondary structure and analyse conformational changes
• Nucleic acid structure determination and changes upon binding or melting
• Other thermodynamic parameters and kinetics based measurements