DNA recovery from ancient tissues: problems and perspectives

The recovery, amplification and sequencing of nucleic acids from ancient smaples opens new possibilities in many different fields, such as anthropology, archeaology, population genetics, animal and plant evolutionary studies, and forensic medicine. The sample processing for DNA extraction and PCR amplification represents the most delicate phase of ancient DNA analysis, with a major impact on the reproducibility and reliability of the results. In this paper some extraction protocols are reviewed and discussed, with particular reference to the removal of the inhibitory substances usually present in extract from ancient tissues. The effect of contamination from extraneous DNA, a possible source of misleading results, is discussed and guidelines to detect and circumvent the problem are given.