DNA quantification is an essential step for successful multiplex short tandem repeat (STR) polymerase chain reactions (PCR), which are used for confirming identities using human genomic DNA. The new DNA quantification kit, named the National Forensic Service Quantification (NFSQ) kit, simultaneously provides total human DNA concentration, human male DNA concentration, and a DNA degradation index (DI) using multiplex TaqMan fluorescent probes. The NFSQ was validated according to developmental validation guidelines from the SWGDAM and MIQE. NFSQ detected up to 0.00128 ng/μL and could detect male DNA up to a 1:8000 ratio of male to female DNA. In PCR inhibitor tests, NFSQ could measure DNA at a concentration of 200 ng/μL of humic acid and 600 μM of hematin. The NFSQ kit showed a DI value trend similar to other qPCR kits. In the reproducibility study, the coefficient of variation of the NFSQ kit was within 10%. The quantitative results of the casework samples obtained using the NFSQ kit were consistent with the STR interpretation results. The NFSQ kit can be useful in the human identification process, as it has detection capabilities similar to those of other comparable quantification kits.
Keywords: DNA quantification; Forensic science; Real-time PCR; Short tandem repeat.