Vaginal swabs: endogenous and postcoital components

Area of Science:

• Forensic Science
• Biochemistry
• Genetics

Background:

• Vaginal swabs are crucial in forensic investigations.
• Accurate identification of biological components is essential for legal proceedings.
• Previous studies have focused on individual markers, but their interrelationships in complex biological matrices are less understood.

Purpose of the Study:

• To investigate the relationships between various components found on vaginal swabs.
• To determine if the presence or quantity of one component can predict others.
• To evaluate the reliability of interpreting grouping results based on single markers.

Main Methods:

• Analysis of vaginal swabs for blood, cellular material, spermatozoa, acid phosphatase, p30, ABH, Lewis, EsD, GLO I, PGM, and PGM subtype.
• Utilized rocket electrophoresis and p-nitrophenyl phosphate assay for acid phosphatase detection.
• Employed rocket and cross-over electrophoresis for p30 analysis.

Main Results:

• Tested 323 semen-free and postcoital vaginal swabs from known donors.
• Seminal acid phosphatase and p30 were detected more frequently using rocket electrophoresis techniques.
• Attributing results to semen based on a single component's reactivity can yield erroneous conclusions.

Conclusions:

• Interactions between seminal and vaginal components can complicate analysis.
• Endogenous vaginal levels of certain markers must be considered for accurate interpretation.
• Forensic interpretation requires a holistic approach, considering multiple biomarkers and their potential interactions.