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Published on: March 9, 2015
High-efficiency 14-plex cSNP SNaPshot assay for forensic peripheral blood identification
Yixia Zhao1, Yuting Sun2, Siyi Wei2
1Institute of Evidence Law and Forensic Science, China University of Political Science and Law, Beijing, 100088, China.
BMC Genomics
|July 11, 2026
Summary
Forensic scientists can now identify bloodstains, even in mixed samples, using a new multiplex assay targeting 14 blood mRNA biomarkers. This method enhances crime scene analysis by differentiating body fluids with high accuracy.
Area of Science:
- Forensic Science
- Molecular Biology
- Genetics
Background:
- Accurate identification of body fluid stains at crime scenes is crucial for forensic investigations.
- Distinguishing between different body fluids, especially in mixed stains, presents a significant challenge.
- Messenger RNA (mRNA) biomarkers offer a promising avenue for differentiating forensic body fluids.
Purpose of the Study:
- To develop and validate a multiplex assay for the identification of peripheral blood using mRNA biomarkers.
- To assess the sensitivity, specificity, and discriminatory power of the developed assay.
- To evaluate the potential of mRNA single nucleotide polymorphisms (cSNPs) for forensic blood identification.
Main Methods:
- Screened 14 cSNPs on four peripheral blood mRNA biomarkers (CD3G, ANK1, SPTB, GYPA).
- Developed a one-step multiplex reverse transcription PCR (RT-PCR) and SNaPshot assay for cDNA amplification and genotyping.
- Assessed assay sensitivity, specificity, and capability on single-source and mixed body fluid samples.
Main Results:
- The 14 cSNP panel successfully identified peripheral blood, including mixed samples.
- The multiplex assay demonstrated a detection sensitivity of 1 ng total RNA.
- Genotyping of 14 cSNP loci in 19 peripheral blood samples showed 100% concordance between DNA- and RNA-derived profiles.
- The cumulative discrimination power of the 14 cSNPs was calculated to be 0.98303 in a Han Chinese population.
Conclusions:
- The developed multiplex SNaPshot assay is effective for forensic blood identification.
- mRNA cSNPs can reliably differentiate peripheral blood from other body fluids like menstrual blood and vaginal secretions.
- This assay provides a valuable tool for forensic analysis, enhancing the identification of blood evidence at crime scenes.
