Melting of DNA

Abstract
An exact statistical‐mechanical treatment is given for the nearest‐neighbor coupled model of DNA, allowing for the difference in bonding stability of the two base pairs, adenine–thymine and gaunine–cytosine. Treatments are given for random as well as pair‐correlated sequences, both for finite and infinite degrees of polymerization. In addition, sequence‐ensemble average thermal properties are compared with the corresponding properties of single molecules. The breadth in temperature of the helix–coil transition is shown to be a marked function of base composition. It is also shown that nonrandomness in nearest‐neighbor base sequence of the magnitude observed in typical bacterial and viral DNA's has little effect on the thermodynamic properties.