Dichroism and Optical Dispersion

These techniques are especially useful for qualitative information on conformational changes the interpretation with respect to defined changes is difficult and may be complicated [28]. 

The shape of the CD curve of DNA is defined as conservative with approximately equal positive and negative areas centered at 260 nm. The spectrum is different to that of the constituent nucleotides and also different from that of RNA. Factors such as tilting of the base pairs or unwinding of the helix may induce alterations in the optical rotation, thus allowing observation of a conformational change that would be undetected by the relatively nonspecific UV spectrum. 

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