Forensic Applications of Body Fluid Identification Techniques

Body fluid identification constitutes a cornerstone of forensic investigations, enabling the reconstruction of events at a crime scene and the link between biological evidence and individuals. Traditional presumptive methods exploit enzymatic or serological reactions to detect unique proteins or antigens, offering rapid on-scene screening. Confirmatory assays, such as immunochromatographic tests, rely on targeted antibody–antigen interactions to distinguish fluids including blood, semen, saliva, vaginal secretions and menstrual blood. Recent advances have expanded beyond protein markers to encompass nucleic acid–based strategies. DNA methylation profiling leverages fluid-specific epigenetic patterns, while mRNA expression assays discriminate tissues by characteristic transcriptional signatures. High-throughput and multiplex methods enhance sensitivity and throughput, allowing simultaneous identification of multiple fluids. Complementary proteomic approaches, using mass spectrometry, detect peptide biomarkers, merging fluid identification with species determination. Emerging trends exploit the forensic microbiome and real-time PCR targeting commensal bacteria to identify older or degraded stains and estimate time since deposition. Integration of these techniques with STR profiling preserves genetic material for donor identification, ensuring both fluid classification and individual attribution. Such multifaceted strategies offer global applicability, supporting investigative and judicial processes through robust, sensitive and specific analyses under varied environmental conditions.

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Forensic Applications of Body Fluid Identification Techniques publication trend

The graph below shows the total number of articles in forensic applications of body fluid identification techniques across all publications each year (not limited to Nature Index journals).

Technical terms

Immunochromatographic test: A rapid assay using antibody–antigen binding on a strip to confirm the presence of specific body fluid proteins.

Short tandem repeat (STR) profiling: Analysis of highly polymorphic DNA loci to identify individuals from biological samples.

Lateral flow assay: Portable paper-based device for rapid detection of target analytes via capillary migration and labelled antibodies.

Microbiome-based analysis: Characterisation of microbial community profiles to identify body fluids and infer time since deposition.

Real-time PCR: Quantitative polymerase chain reaction method that monitors amplification of DNA targets, used for detecting specific bacterial DNA markers.

DNA methylation profiling: Assessment of fluid-specific epigenetic marks to differentiate between body fluids.

mRNA profiling: Measurement of transcript levels of tissue-specific genes to determine the origin of biological samples.

References

1. Assessment of Blood and Semen Detection and DNA Collection from Swabs up to Three Months after Deposition on Five Different Cloth Materials. International Journal of Molecular Sciences (2024).
2. Use of Lateral Flow Assays in Forensics. Sensors (2023).
3. Methylation Markers for the Identification of Body Fluids and Tissues from Forensic Trace Evidence. PLOS ONE (2016).
4. Development of Highly Sensitive and Specific mRNA Multiplex System (XCYR1) for Forensic Human Body Fluids and Tissues Identification. PLOS ONE (2014).
5. Mass spectrometry-based proteomics as a tool to identify biological matrices in forensic science. International Journal of Legal Medicine (2012).
6. Body fluids should be identified before estimating the time since deposition (TsD) in microbiome-based stain analyses for forensics. Microbiology Spectrum (2024).
7. Rapid oral bacteria detection based on real-time PCR for the forensic identification of saliva. Scientific Reports (2018).