Evaluation of Degradation in DNA from Males with a Quantitative Gender Typing, Endpoint PCR Multiplex

Abstract

Evidentiary samples submitted to a forensic DNA laboratory occasionally yield DNA that is degraded. Samples of intact chromosomal DNA (both nuclear and mitochondrial) were subjected to a heating protocol to induce DNA degradation. The DNAs were then analyzed using a multiplex PCR assay that amplifies targets of low and high molecular weight on the X/Y and mitochondrial chromosomes. If degradation is random, the amplification of larger DNA targets should be more adversely affected by degradation than smaller targets. In nuclear and mitochondrial DNA from a male donor, exhibiting degradation, DNA quantity estimates based upon higher molecular weight amplicons (HMW) are significantly lower than estimates made using low molecular weight (LMW) Q-TAT amplicons. DNA degradation estimated using this approach correlated well with actual fluorescence associated with HMW and LMW STR alleles amplified from the same genomic DNA templates. Q-TAT is thus useful not only as a quantitation tool, but also as an indicator of template degradation.

Improving STR Profile Success Rates for Property Crime Specimens using InnoQuant® Human DNA Quantification & Degradation Assessment Kit

“…The use of assays to provide information about the degradation state of a forensic sample has been previously published [19][20][21][22]. Laboratories that process forensic samples, particularly those that identify human remains which may be in an increased state of degradation, greatly benefit from having information regarding the quality or integrity of a sample prior to PCR amplification of the typing system.…”