Developmental validation of the PowerPlex® Y23 System: a single multiplex Y-STR analysis system for casework and database samples.

The PowerPlex® Y23 System combines the seventeen Y-STR loci in current commercially available Y-STR kits (DYS19, DYS385a/b, DYS389I/II, DYS390, DYS391, DYS392, DYS393, DYS437, DYS438, DYS439, DYS448, DYS456, DYS458, DYS635, and Y-GATA-H4) with six new highly discriminating Y-STR loci (DYS481, DYS533, DYS549, DYS570, DYS576, and DYS643). These six new loci have higher gene diversities than most of the loci in other commercial Y-STR analysis kits, allowing for further distinction between unrelated male individuals. In addition, the inclusion of two rapidly mutating Y-STR loci may allow for the discrimination of related individuals. The PowerPlex® Y23 System is designed to amplify DNA from purified extracts as well as direct amplification from substrates used to collect database samples (e.g. swabs and storage cards). Validation of the PowerPlex® Y23 System includes all of the studies required by the FBI and SWGDAM. The results demonstrate that the PowerPlex® Y23 System is a robust and reliable amplification kit capable of overcoming high concentrations of commonly encountered inhibitors such as hematin, humic acid, and tannic acid. Full profiles are consistently detected with 62.5 pg of male DNA, even in the presence of excessive amounts of female DNA, establishing the PowerPlex(®) Y23 System as a sensitive method for Y-STR testing. Complete Y-STR profiles are detected from mixed samples with 62.5 pg of male DNA in a background of 400 ng of female DNA or 125 pg of male DNA mixed with 3000 ng of female DNA.

Developmental validation of the PowerPlex® 18D System, a rapid STR multiplex for analysis of reference samples.

As short tandem repeat markers remain the foundation of human identification throughout the world, new STR multiplexes require rigorous testing to ensure the assays are sufficiently robust and reliable for genotyping purposes. The PowerPlex(®) 18D System was created for the direct amplification of buccal and blood samples from FTA(®) storage cards and reliably accommodates other sample materials. The PowerPlex(®) 18D System allows simultaneous amplification of the 13 CODIS loci and amelogenin along with four additional loci: Penta E, Penta D, D2S1338, and D19S433. To demonstrate suitability for human identification testing, the PowerPlex(®) 18D System was tested for sensitivity, concordance, inhibitor tolerance, and performance with thermal cycling and reaction condition variation following SWGDAM developmental validation guidelines. Given these results, PowerPlex(®) 18D System can confidently be used for forensic and human identification testing.