Animal DNA in PCR reagents plagues ancient DNA research

• Published in: Journal of archaeological science Vol. 34; no. 9; pp. 1361 - 1366
• Main Authors: Leonard, Jennifer A., Shanks, Orin, Hofreiter, Michael, Kreuz, Eva, Hodges, Larry, Ream, Walt, Wayne, Robert K., Fleischer, Robert C.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Ltd 2007; Elsevier Science
• Subjects: Archaeology subjects; Arkeologiämnen; Biologi; Biology; Bos taurus; Deoxynucleoside triphosphates; Excavation and methods; Gallus gallus; Historisk-filosofiska ämnen; History and philosophy subjects; HUMANIORA och RELIGIONSVETENSKAP; HUMANITIES and RELIGION; Laboratory methods; Methodology and general studies; NATURAL SCIENCES; NATURVETENSKAP; Physical and chemical analysis; Prehistory and protohistory; Sus scrofa; Bos taurus; Sus scrofa; Deoxynucleoside triphosphates; Gallus gallus; Polymerase chain reaction; Plant; DNA; Animal; Anthropology; Evolution; Ecology; Molecular biology
• ISSN: 0305-4403; 1095-9238; 1095-9238
• DOI: 10.1016/j.jas.2006.10.023

Molecular archaeology brings the tools of molecular biology to bear on fundamental questions in archaeology, anthropology, evolution, and ecology. Ancient DNA research is becoming widespread as evolutionary biologists and archaeologists discover the power of the polymerase chain reaction (PCR) to amplify DNA from ancient plant and animal remains. However, the extraordinary susceptibility of PCR to contamination by extraneous DNA is not widely appreciated. We report the independent observation of DNA from domestic animals in PCR reagents and ancient samples in four separate laboratories. Since PCR conditions used in ancient DNA analyses are extremely sensitive, very low concentrations of contaminating DNA can cause false positives. Previously unidentified animal DNA in reagents can confound ancient DNA research on certain domestic animals, especially cows, pigs, and chickens.