การทดสอบประสิทธิภาพและตรวจเปรียบเทียบชุดน้ำยา AmpFISTR® Identifiler® Plus PCR Amplification กับ QIAGEN® Investigator IDplex Plus

Abstract

Commercial STR typing kits are used by forensic laboratories worldwide. DNA Analysis Center, Scientific Crime Detection Division 10, Royal Thai Police, employs the AmpFLSTRR Identifiler® Plus kit. Later on QIAGENR commercialized another STR kit that targets the same 15 loci. If the performance of the two kits are on par, switching to the QIAGENR Investigator® IDplex Plus could reduce cost and investigation time. This study compared the performance of the AmpFLSTRR Identifiler® Plus PCR Amplification kit and the QIAGEN® Investigator® IDplex Plus kit. We evaluated peak height, percent profile, intra-locus balance, inter-locus balance, stutter ratio, allelic drop-out and allelic drop-in using both control DNA samples and casework samples. Sensitivity test with different amounts of 9947A and 9948 DNA was performed. Three common PCR inhibitors, including humic acid, hematin and calcium, were spiked into PCR reactions to test for inhibitor tolerance. Casework samples were also used. The findings of this study demonstrate that the IDplex Plus kit is more sensitive than the Identifiler® Plus. However, the higher success rate of STR typing was obtained in Identifiler® Plus judging by the average number of allele detected. The IDplex Plus kit was more tolerant to inhibitors tested. Stutter values for all loci were within the expected range of less than 0.15 by both kit. Our result suggested that IDplex Plus kit has the ability to replace the current STR kit in the current workflow, without the need to replace or upgrade instrument and database.