The use of mini-STRs on degraded DNA samples

Abstract Forensic laboratories – more frequently than in the recent past – are beginning to study degraded and/or compromised DNA. These samples usually contain small amounts of DNA (LCN DNA). With these exhibits, even relying on the most efficient extraction system, or amplifying with increased number of PCR cycles, the STRs profiles are often incomplete or exposed to stochastic effects. In this paper we refer to the use of a mini-pentaplex (FGA, D21S11, CSFPO, D7S820 and TH01) and a mini-quadruplex (Penta D, D2S1338, Amelogenin, and D18S51) used to analyse casework samples which gave negative or very partial results, when analysed by the commercially available kits. The preliminary results obtained from this study are promising and in this report we demonstrate that we can obtain profiles with relatively lower quantity of DNA (approximately 50 pg or less) in a reliable manner.