One of the principal applications of Chirascan™ is in determining the secondary structure of proteins and it is also used to investigate their tertiary structure by measuring the CD induced in the aromatic side-chains and disulphide bonds of the peptide backbone.
Protein secondary and tertiary structures change under stress, for example with temperature or pH, and circular dichroism is used to assess conformational stability with changing environment. Used in this way, it has an important role to play in biotherapeutic drug development and formulation testing (see Applications) where it can help to optimise buffer conditions that enhance product longevity. Circular dichroism is also used in bio-comparability studies to demonstrate conformational equivalence of material from different processes or sources and for determining that novel proteins are correctly folded.