cot curve

A method to estimate the heterogeneity of sequence of a DNA preparation, based on the observation that the more homogenous the DNA, the more easily (and therefore faster) the annealing of single-stranded DNA will occur. The Cot curve plots the extent of annealing from a fully single-stranded preparation over time. The cot (product of initial concentration and time) at which half the DNA has re-natured is the half-cot, a parameter indicating both the degree of heterogeneity in a complex mixture, and of the extent of complementarity in a mixture of two single-stranded DNA molecules.