A Comparative Analysis of the AmpFlSTR Identifiler and PowerPlex 16 Autosomal Short Tandem Repeat (STR) Amplification Kits on the Skeletal Remains Excavated from Second World War Mass Graves in Slovenia

Abstract

Aim. This paper describes a comparative study of two different amplification kits for autosomal STR typing of skeletal remains excavated from Second World War mass graves in Slovenia. We analyzed 92 bones and teeth and compared the genetic profiles obtained using the AmpFlSTR IdentifilerTM Amplification Kit (Applied Biosystems) and the PowerPlex 16 System (Promega). Methods. We cleaned the bones and teeth, removed surface contamination and ground them into a powder using liquid nitrogen. Prior to deoksiribo nucleic acid (DNA) isolation with Biorobot EZ1 (Qiagen), 0.5g bone or tooth powder was decalcified. The nuclear DNA of the samples was quantified using the real-time polymerase chain reaction (PCR) method. The amplification protocols for both kits were optimised for old skeletal remains. Results. We extracted 0.4 to 100 ng DNA/g of powder from the bones and teeth. Both amplification kits showed very similar efficiency on the 70 year old bones and teeth, since DNA typing was successful in 81 out of the 92 bones and teeth with both amplification kits, which represent an 88% success rate. Conclusions. The comparative study indicated that the commercially available Identifiler and PowerPlex 16 PCR amplification kits are reliable for short tandem repeat (STR) typing of World War II skeletal remains with the DNA extraction method and PCR amplification conditions optimised in our laboratory, since very often complete STR profiles of autosomal DNA were obtained with both kits.