An STR melt curve genotyping assay for forensic analysis employing an intercalating dye probe FRET

The most common markers used in forensic genetics are short tandem repeats (STRs), the alleles of which are separated and analyzed by length using capillary electrophoresis (CE). In this work, proof of concept of a unique STR genotyping approach has been demonstrated using asymmetric PCR and a fluorescence resonance energy transfer (FRET)-based hybridization analysis that combines fluorophore-labeled allele-specific probes and a DNA intercalating dye (dpFRET) in a melt match/mismatch analysis format. The system was successfully tested against both a simple (TPOX) and a complex (D3S1358) loci, demonstrated a preliminary detection limit of <10 genomic equivalents with no allelic dropout and mixture identification in both laboratory-generated and clinical samples. With additional development, this approach has the potential to contribute to advancing the use of STR loci for forensic applications and related fields.