Assessing the effects of conservation treatments on short sequences of DNA in vitro

Little is known about what effects conservation treatments used to preserve human and animal hard and soft tissues have on DNA preservation. We have developed a method to assess quantitatively the extent of lesions or strand breakage caused by conservation treatments on short sequences of DNA in vitro. The method developed enables the determination of the percentage of DNA preserved following exposure to a conservation treatment solution relative to control samples, thereby allowing the direct comparison of treatments based upon their preserving/damaging effects on a DNA sequence. Forty-three chemicals commonly used in the preparation and/or conservation of human and/or animal remains were examined. We found that the majority were damaging, in particular and as expected, acidic treatments and treatments carried out at elevated temperatures. A few, primarily organic solvents, were not damaging. The approach we have adopted can be applied to screen other treatments either used in the past or for future conservation applications as they are developed to assess their effects on DNA. How these results should be interpreted in terms of conservation and sampling is also discussed.