EXPERIMENTAL TESTS OF THE PEYRARD-BISHOP MODEL APPLIED TO THE MELTINGOF VERY SHORT DNA CHAINS

The melting curves of short heterogeneous DNA chains in solution are c alculated on the basis of statistical thermodynamics, and compared to experiments. The computation of the partition function is based on the Peyrard-Bishop Hamiltonian, which has already been adopted in a theor etical description of the melting of long DNA chains. In the case of s hort chains it is necessary to consider not only the breaking of the h ydrogen bonds between single base pairs, but also the complete dissoci ation of the two strands forming the double helix.