Jaroslav Pavelka

Sediments contaminated by allochthonous animal proteins present a challenge to molecular archaeology

Jaroslav Pavelka§, Ladislav Smejda#

§ University of West Bohemia in Pilsen, Center of biology, Klatovská 51, 306 19 Pilsen, Czech Republic; # Department of Archaeology, University of West Bohemia, Univerzitni 8, 30614, Plzen, Czech Republic

Research on ancient proteins preserved in archaeological contexts needs to consider the problem of recent protein contamination. Using an ELISA immunological test designed to identify cooked pork, we found that pig proteins were present in the studied pottery specimens, but the surrounding soil contained only uncooked pig proteins. We interpret this observation in the sense that the ceramic vessels did serve for cooking pork in the historic times. Pig proteins identified in soil matrix are of different origin, however, and represent probably contamination from dung, dropped by wild pigs living in the area of the sampled archaeological site until the present day. Our study opens a new perspective of dealing with the complexities of research into archaeological biomolecules, suggesting that typical study sites may contain a mixture of ancient raw and artificially processed proteins as well as original protein content plus secondarily introduced/contaminating proteins (and other types of biomolecules) of the same species.