Proximity Ligation Real-Time PCR: A protein-based confirmatory method for the identification of semen and sperm cells from sexual assault evidence
Related Experiment Video
Updated: Feb 6, 2026

Avian Semen Collection by Cloacal Massage and Isolation of DNA from Sperm
Published on: February 5, 2018
Sarah Riman1, Chin Hong Shek2, Michelle A Peck3
1Department of Forensic Sciences, The George Washington University, 2100 Foxhall Road NW, Washington, DC 20007, USA; National Institute of Standards and Technology, Biomolecular Measurement Division, 100 Bureau Drive, Gaithersburg, MD 20899, USA.
Abstract:
The positive identification of seminal fluids in sexual assault crimes is considered crucial evidence to determine whether a sexual act occurred or not. However, current presumptive methods lack specificity and sensitivity. Confirmation of semen by microscopic examination of spermatozoa is laborious, time consuming, and can sometimes lead to negative or inconclusive results. Here we report the use of the Proximity Ligation Real-Time PCR (PLiRT-PCR) assay as an attractive and promising confirmatory method for the identification of semen and sperm proteins using two polyclonal antibodies, Prostate Specific Antigen (PSA) and Sperm-Specific Protein (SP10), respectively. PLiRT-PCR, relies on protein recognition by pairs of proximity probes (antibody-DNA conjugates) that give rise to a ligated DNA strand. The ligated DNA strand is then amplified and detected by qPCR.
Related Concept Videos
Sperm Structure and Semen Composition
Real Time RT-PCR
The real-time quantification of the number of amplified products is...
The Evidence for Evolution
Methods of Classification and Identification
PCR
Sperm Transport
The maturation phase occurs in the epididymis, where sperm...

