Recovery and identification of DNA sequences harboured in preserved ancient human bones.

A new method is presented to extract and identify specific DNA fragments from well preserved human bones, dating from three different time periods. Bone samples were thoroughly freed from surfacial contaminating DNA. Access to the inner bone spongiosum was achieved by removing the covering bone layers of the vertebra or sternum, whereas the patella, tibia and caput of the femur or humerus were cleaved with an iron saw. After the spongiosum was taken out, extraction of nucleic acids from this "sand" like material was performed by heating at 94 degrees C during 20 min in a buffer containing essentially minor concentrations of detergent, chelating and reducing agents. The extracts were used in various Polymerase Chain Reaction (PCR) protocols to amplify different human specific DNA fragments (originating from chromosomes X and 12). From 15 out of 20 bone samples human-specific gene fragments could thus be identified.