Circular Dichroism spectroscopy is a powerful technique that is sensitive to the chirality (handedness) of molecules. It provides a means of studying absolute stereochemistry, enantiomeric composition, racemisation, enantio-discriminatory phenomena and molecular interactions. Furthermore it is often the method of choice for studying the higher-order structure of biomacromolecules such as proteins, glycoproteins and DNA; subtle changes in the folding and the environment of chromophoric groups can be detected. The binding and association of achiral species to chiral moeties (e.g. drug-protein or drug-DNA) can also be probed through their induced CD.