Credit: B. SHAPIRO & A. COOPER

Proc R. Soc. B 10.1098/rspb.2009.0563 (2009)

Palaeontologists may need to find a better way to predict the integrity of DNA in ancient remains.

Processes to extract DNA from fossils can cause considerable specimen damage (as pictured). To avoid needless destruction, researchers have tended to screen samples first, measuring the extent of aspartic acid racemization — the chemical conversion of the amino acid to a different form over time — to estimate protein integrity. The belief was that if proteins remained intact, so too did DNA. Now Matthew Collins at the University of York, UK, and his colleagues reveal that this is not the case.

They studied 91 specimens of tooth and bone, evaluating how protein analysis compared with rates of DNA amplification success. Racemization offered little information on the quality of the DNA in a fossil.