A PRELIMINARY INVESTIGATION OF DNA STABILITY IN BONE DURING ARTIFICIAL DIAGENESIS

DNA extracted from ancient organic remains has much to offer anthropol ogy and archaeology, but post-mortem damage can inhibit molecular biol ogical techniques or produce incorrect sequence determinations. There have been few studies on the diagenesis of DNA and, as yet, little is known about how and why the molecule might survive over thousands or m illions of years. Qualitative analysis of nucleic acids extracted from powdered bovine bone which had been heated to various temperatures in the presence and absence of water, revealed that the DNA had become f ragmented. In the wet samples this decay was so extensive that mitocho ndrial DNA could not be amplified by the Polymerase Chain Reaction (PC R). Immunochemical detection of the DNA showed that substantial quanti ties of DNA remained in some samples for which a PCR product could not be obtained. The results of the DNA analyses are compared with theore tical estimates of DNA decay and protein survival in the same samples. Reasons for the disparity between the immunochemical and PCR data, su ch as interference of the PCR, are considered. It is concluded that hy drolytic chain scission events have much more impact on the loss of th e long sequences of DNA required for PCR than on the numbers of shorte r antibody binding sires detected by immunochemistry.