Sensitivity and Specificity in Forensic Context
Definition
Sensitivity is the probability of a positive result when semen is truly present; specificity is the probability of a negative result when semen is absent. For confirmatory semen tests, both must be high. PSA can give weak false positives from breast tissue; RSID-Semen has near-100% specificity for semen among human body fluids tested.
Related terms
- ABAcard P30 (HemaTrace P30)
- A lateral-flow immunochromatographic card that detects PSA at approximately 0.2-4 ng/mL of extract. Widely used in sexual assault kit triage because it...
- Prostate-Specific Antigen (PSA / P30)
- A glycoprotein produced by the prostate gland and secreted into seminal plasma at high concentrations. The PSA immunochromatographic strip test is the...
- RSID-Semen
- Rapid Stain Identification of Semen: an immunochromatographic lateral-flow strip from Independent Forensics that detects semenogelin I and II with sensitivity to approximately...
- Semenogelin I and II
- High-molecular-weight proteins secreted by the seminal vesicles that form the semen coagulum immediately after ejaculation. PSA then cleaves them to liquefy the...
- Seratec PSA Semiquant
- A lateral-flow PSA strip with a semi-quantitative band-intensity scale. Line intensity corresponds approximately to 1 ng/mL, 2 ng/mL, or greater concentrations, useful...
Explained in
- p30/PSA and RSID-SemenSensitivity is the probability of a positive result when semen is truly present; specificity is the probability of a negative result when semen is absent. For...