High-resolution melt analysis of DNA methylation to discriminate semen in biological stains

Anal Biochem. 2016 Feb 1:494:40-5. doi: 10.1016/j.ab.2015.10.002. Epub 2015 Oct 22.

Abstract

The goal of this study was to develop a method for the detection of semen in biological stains using high-resolution melt (HRM) analysis and DNA methylation. To perform this task, we used an epigenetic locus that targets a tissue-specific differentially methylated region for semen. This specific locus, ZC3H12D, contains methylated CpG sites that are hypomethylated in semen and hypermethylated in blood and saliva. Using this procedure, DNA from forensic stains can be isolated, processed using bisulfite-modified polymerase chain reaction (PCR), and detected by real-time PCR with HRM capability. The method described in this article is robust; we were able to obtain results from samples with as little as 1 ng of genomic DNA. Samples inhibited by humic acid still produced reliable results. Furthermore, the procedure is specific and will not amplify non-bisulfite-modified DNA. Because this process can be performed using real-time PCR and is quantitative, it fits nicely within the workflow of current forensic DNA laboratories. As a result, it should prove to be a useful technique for processing trace evidence samples for serological analysis.

Keywords: Body fluid identification; DNA methylation; Epigenetic; Forensic; High-resolution melt; Real-time PCR.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Body Fluids / metabolism
  • DNA / analysis*
  • DNA / blood
  • DNA Methylation
  • Epigenomics
  • Forensic Genetics / methods*
  • Humans
  • Humic Substances / analysis
  • Male
  • Phase Transition
  • Real-Time Polymerase Chain Reaction
  • Saliva / metabolism
  • Semen / metabolism*
  • Sulfites / chemistry
  • Transition Temperature

Substances

  • Humic Substances
  • Sulfites
  • DNA
  • hydrogen sulfite