Dual DNA-protein extraction from human archeological remains

Human skeletal remains may be considered bio-archives due to their particular combination of mechanical, structural, and chemical properties that render natural resistance against post-mortem degradation of ancient biomolecules. The survival of organic matter in ancient tissues is of great interest due to its potential in recovering information on the historical past of individuals and populations including health, dietary history, ancestry, and migration patterns. Even though the ancient biomolecules have become a powerful research tool, the archeogenetic research field can often deal with obstacles regarding the limited availability of osteological material and/or ethical concerns as their analysis is destructive. Here, we describe an alternative, efficient method for simultaneous extraction of DNA and proteins from the same archeological sample source, thus limiting the damage to valuable ancient human skeletal remains. The proposed method consists of overnight decalcification of powdered tissue, purification and concentration of biomolecules, and separation of the resulting solution for subsequent DNA purification and protein precipitation. Its performance was assessed relative to previously described approaches, comparing the concentration of the retrieved biomolecules. Our results show that this method designed to co-purify DNA and proteins is appropriate to obtain authentic sequences of the human mitochondrial control region from medieval or more recent human teeth. Also, the resulting proteins can be used for immunochromatographic detection of malaria in skeletal material suspect of infection with Plasmodium sp.