Chargaff’s Cluster Rule

Abstract

A nucleic acid sequence has three fundamental characteristics – its length, its base composition, and its sequence. If you know the sequence then you can calculate length and base composition with great precision. However, before the emergence of sequencing technologies in the 1970s there were biochemical methods that could provide values for length and base composition, albeit less precisely. Furthermore, Chargaff and his colleagues developed a method for evaluating a particular sequence characteristic – base clustering – that could distinguish DNA samples on the basis of sequence differences.