Paternity testing on exhumed bodies: old problems and new strategies

There is an increasing demand for paternity testing from exhumed bodies in our routine. DNA extraction from human bones is known to be a difficult and time consuming procedure, and all the cases investigated in this study showed these typical difficulties. We focused our attention on nails as an alternative source of DNA in those cases when no result was obtained from bones; commercial DNA extraction columns were also tested on bones in comparison to standard DNA extraction procedures. DNA extraction was performed from compact diaphyseal femoral bone tissues using either the organic technique or commercial columns. DNA from nails was extracted with organic method. Standard PCR was performed using commercial forensic kits and the amplified fragments were resolved on automatic instruments. Nails proved to be a good alternative source of DNA, both in terms of DNA yield and of reduced amount of time requested for analysis. Commercial columns gave better results when compared to standard organic extraction on bone extracts. Other advantages and disadvantages of this approach are discussed.