Diamond Light Source
Beamline B23 - Circular Dichroism

Circular Dichroism (CD) is the spectroscopic technique to study in solution a wide variety of chiral materials such as small molecules (drugs), polymers and biopolymers (nucleic acids, proteins, carbohydrates and lipids). In particular for proteins, knowledge of the structure-function relationship is essential to dissect the mode of action and to identify new targets for novel drug therapeutics.

For rigid and well structured systems, like enzymes and globular proteins, CD is a low-resolution technique compared to NMR and X-ray crystallography. However, a third to half of mammalian proteins have natively disordered structures that are unsuitable for NMR and X-ray crystallography. CD is the ideal technique to investigate protein/ligand binding interactions of these important systems involved in signal transduction of normal and tumour cells.

B23 producesa collimated beam of small cross section at the sample (about 1mm (V) x 2mm (H)) enabling the measurement of smaller volumes of sample solutions several times better than commercial CD instruments. High photon flux across the UV region improves the signal-to-noise of CD measurements.

B23 is used by researchers in the biological, biochemical, chemical, pharmaceutical, and crystallographic sciences to examine proteins, nucleic acids, carbohydrates, biopolymers, small ligands and the interactions of these molecules to form macromolecular and drug complexes.

  • Operational Module B: 165-650nm wavelength range
  • Operational Module A: 125-500nm wavelength range
Beamline Energy Range
2 - 10 [eV]
Giuliano Siligardi
  • UVCD
control/Data analysis
Control Software Type
  • Customised Olis SpectralWorks
Data Output Type
  • spectra, temperature and time
Data Output Format
  • .ols and ascii
Softwares For Data Analysis
  • In-house CD-Apps