Validation of the PowerPlex Fusion 6C system: a six-dye STR system for forensic case applications

The PowerPlex Fusion 6C system is a six-dye STR multiplex that allows co-amplification and fluorescent detection of 27 loci, including Amelogenin, 23 autosomal STR loci and 3 Y chromosome STR loci. In this study, this system was validated using upgraded 3130xl Genetic Analyzers for sensitivity, species specificity, stability, DNA mixtures, reproducability, case-type samples, stutter, concordance, and PCR conditions following the Scientific Working Group on DNA Analysis methods (SWGDAM) developmental validation guidelines and Chinese National Standard (GA/T815-2009). The results show this system is sensitive, species-specific, accurate and genotype-consistent compared with the PowerPlex A (R) 21 system for detecting 100 samples, and robust for changes in several PCR conditions or exposure to PCR inhibitors. The results of casework indicate that Y-STR loci of the PowerPlex Fusion 6C system may help to recognize mixed and very-low-ratio male DNA. The population data of 274 unrelated Chinese Han individuals suggests that this multiplex system is suitable for human identification and paternity testing in Guangdong Han population. The data demonstrate that the PowerPlex Fusion 6C system is a robust and reliable STR-typing multiplex, and is especially advantageous for some case samples.