DNA Human Identification from Forensic Bone Fragments

Instrument: Precellys® 24

Sample: Human bone fragments

Protocol:

  • Grind 200 mg of bone fragments in liquid nitrogen in a freezer mill
  • Add the ground bone fragment to 2 ml hard tissue homogenizing kit.
  • Add 400 µl of phenol-chloroform extraction buffer
  • Run the precellys at 5900 rpm, 2 x 30 seconds with a 50 second break.
  • Purify the DNA via a purification column (in this case a Microcon column was used)

Results:

The Precellys 24 was compared to the conventional method (grinding followed by overnight incubation at 56°C with 15 µl of Proteinase K).  Analysis was performed using PCR amplification followed by visualization on an ABI PRISM 310 analyzer.  Seven samples were analyzed in this method, having been taken from carbonized bodies and corpses.  In all cases, DNA extraction using the conventional protocol did not give a good result (15 autosomic loci).  In these cases, all results were considered inconclusive.  The genetic profile was achieved in six out of seven inconclusive tests, giving a genetic profile positive result of 85,7% of the samples processed on the Precellys®24 (see the table below). Only one case was not concluded, due to a high level of sample degradation.

Table of results for the seven forensic bone fragments tested.

Results for the seven samples. CM= Conventional Method, P24= Precellys®24 method, BF= bone fragment, Inc= inconclusive result, Conc.= conclusive result