Sequence variants have been observed in short tandem repeat (STR) loci, but are not detected with conventional electrophoretic analyses. We have validated a high-throughput assay providing base composition analysis of the thirteen CODIS STR loci plus the amelogenin locus. Alleles are amplified with an 8-well panel and the PCR products are directly analyzed on an automated electrospray ionization-mass spectrometry (ESI-MS) platform. The resulting mass determinations are converted to base compositions specifying the number of each of the nucleotides in the PCR amplicons, and STR profiles are derived from the base compositions. Notably, the accuracy of the mass measurements supports detection of sequence variants of STR alleles. Here we describe the developmental validation of the assay and summarize results from analysis of sample panels characterizing allele frequencies, the inheritance of SNP alleles, and the occurrence of germ line mutations in trio sample sets.
|Journal||Forensic Science International: Genetics Supplement Series|
|State||Published - Dec 2011|
- Mass spectrometry
- STR typing
- Variant allele