Computer simulation of DNA ligation: determination of initial DNA concentrations favouring the formation of recombinant molecules.

A computer program was used to simulate the dynamic process of a ligation of DNA fragments. More specifically, the influence of the initial DNA fragments lengths and concentrations on the relative abundance of the various end-products was systematically investigated. Depending on the nature of the DNA extremities (asymmetric or symmetric, dephosphorylated or not), sets of initial conditions could be found that optimized the yield of active recombinant molecules. These results can be directly used to increase the efficiency of the ligation step, in particular for the construction of cDNA or genomic libraries.