Comparison of extractable DNA from bone following six-month exposure to outdoor conditions, garden loam, mold contamination or room storage.

Femur bone sections from a single donor were exposed for six months to (i) outdoor conditions (exposure to sun, rain, etc.); (ii) water-vapour saturated environment favourable to mould proliferation and (iii) humic-garden soil. Following these treatments, DNA was extracted and yields were compared with that of a control bone fragment kept under optimal laboratory storage conditions. Our results demonstrate that both mould and soil are very detrimental to bone DNA conservation since more than 97% of the bone DNA was lost in these samples as compared with the control condition. Outdoor exposure gives an intermediate result with 30% of the DNA still present in the bone. Thus, environments favourable to microorganisms proliferation appear detrimental to bone DNA conservation and are a bad prognostic should bone remains be used for genetic identification purpose. Comparatively, open-air exposure is much more favourable to bone DNA analysis.