Genetic identification of decomposed cadavers using nails as DNA source

Blood or muscle can be used as a DNA source for the genetic identification of recently deceased persons. If the post mortem interval increases, bones and teeth are used. In this case, collection and DNA isolation will be more difficult and time consuming. The aim of this study was to evaluate the use of nails as an alternative DNA source for the genetic identification of decomposed cadavers. DNA extraction from 5mg of fingernails from 7 volunteers using 1h cell lysis in a standard buffer and a DNA purification on QIAamp DNA mini kit columns allowed to acquire a mean quantity of 100 ng DNA/mg nail. This was unexpected, as blood and muscle contain comparable amounts of DNA. Our protocol allowed to obtain full PowerPlex 16 DNA profiles from 10 cadavers characterized by post mortem intervals ranging from 5 days to more than 6 months. The good quality of these profiles indicated that DNA from nail is well preserved. In conclusion, nails are very easy to collect and contain large amounts of good quality DNA that can be extracted within a few hours. They may therefore represent an attractive DNA source not only for routine, but also for urgent genetic identification of decomposed cadavers.