Repair of degraded duplex DNA from prehistoric samples using Escherichia coli DNA polymerase I and T4 DNA ligase.

The most notable feature of DNA extracted from prehistoric material is that it is of poor quality. Amplification of PCR products from such DNA is consequently an exception. Here we present a simple method for the repair of degraded duplex DNA using the enzymes Escherichia coli DNA polymerase I and T4 DNA ligase. Adjacent sequences separated by nicks do not split up into intact strands during the denaturation step of PCR. Thus the target DNA is refractory to amplification. The proposed repair of nicked, fragmented ancient DNA results in an increase of amplification efficiency, such that the correct base order of the respective nuclear DNA segment can be obtained.