A comprehensive study into false positive rates for 'other' biological samples using common presumptive testing...

Area of Science:

• Forensic Science
• Biochemistry
• Immunology

Background:

• Forensic science relies on tests to identify biological fluids, but many exhibit false positives.
• Current reporting of results often lacks robust support for conclusions due to limited data on cross-reactions.

Purpose of the Study:

• To investigate the specificity of common presumptive tests for blood, semen, and saliva.
• To address gaps in the literature regarding cross-reactions with 'other' biological samples.

Main Methods:

• Evaluated the specificity of 11 widely used presumptive tests (chemical, biological, immunochromatographic).
• Tested Luminol, TMB/Combur³ Test® E, Kastle-Meyer (KM), RSID™-Blood, ABAcard® HemaTrace®, Acid Phosphatase (AP), ABAcard® p30, RSID™-Semen, Phadebas® 'Tube' Test, Phadebas® 'Press' Test, and RSID™-Saliva.
• Tested against known volunteer samples of blood, semen, saliva, urine, sweat, vaginal material, feces, and breast milk.

Main Results:

• Determined false positive rates for each tested presumptive test.
• Quantified cross-reactions between various biological materials and forensic screening tests.

Conclusions:

• The study provides crucial data on the specificity of common forensic presumptive tests.
• Findings will aid forensic scientists in providing more robust support for test result interpretations and reducing misinterpretation.