Qiagen's Investigator™ Quantiplex Kit as a predictor of STR amplification success from low-yield DNA samples.

Qiagen's Investigator™ Quantiplex kit, a total human DNA quantitation kit, has a 200-base pair internal control, fast cycling time, and scorpion molecules containing a covalently linked primer, probe, fluorophore, and quencher. The Investigator™ Quantiplex kit was evaluated to investigate a value under which complete short tandem repeat (STR) failure was consistently obtained. Buccal swabs were extracted using the Qiagen QIAamp(®) DNA Blood Mini Kit, quantified with the Investigator™ Quantiplex kit using a tested half-volume reaction, amplified with the ABI AmpFlSTR(®) Identifiler kit, separated on the 3100Avant Genetic Analyzer, and data analyzed with GeneMapper(®) ID v.3.2. While undetected samples were unlikely to produce sufficient data for statistical calculations or CODIS upload (2.00 alleles and 0.82 complete loci on average), data may be useful for exclusionary purposes. Thus, the Investigator™ Quantiplex kit may be useful for predicting STR success. These findings are comparable with previously reported data from the Quantifiler™ Human kit.