Developmental Validation of RSID™‐Semen: A Lateral Flow Immunochromatographic Strip Test for the Forensic Detection of Human Semen*

Abstract

Tests for the identification of semen commonly involve the microscopic visualization of spermatozoa or assays for the presence of seminal markers such as acid phosphatase (AP) or prostate-specific antigen (PSA). Here, we describe the rapid stain identification kit for the identification of semen (RSID™-Semen), a lateral flow immunochromatographic strip test that uses two antihuman semenogelin monoclonal antibodies to detect the presence of semenogelin. The RSID™-Semen strip is specific for human semen, detecting <2.5 nL of semen, and does not cross-react with other human or nonhuman tissues tested. RSID™-Semen is more sensitive with certain forensic evidence samples containing mixtures of vaginal secretions and semen than either of the commercially available PSA-based forensic semen detection tests or tests that measure AP activity that were tested in parallel. The RSID™-Semen kit also allows sampling a fraction of a questioned stain while retaining the majority of the sample for further processing through short tandem repeat analysis.

The effect of mark enhancement techniques on the subsequent detection of saliva

“…The saliva test denoted a negative reaction for many different types of animal saliva; however, it denoted a positive reaction for gorilla saliva [27]. A number of studies [6,28] reported the RSID TM -Saliva kit as more sensitive and specific in comparison to the SALIgAE® and Phadebas® tests.…”

“…RSID TM -Saliva utilizes two anti-salivary α-amylase monoclonal antibodies to detect the presence of salivary amylase, rather than the activity of the enzyme and the manufacturer reports the test as accurate, reproducible, easy to use, and highly specific for human saliva [27]. Once a stain is detected, the remaining extract can then be submitted for DNA analysis since the test is not detrimental to such analysis.…”

Evaluation of Rapid Stain IDentification (RSID™) Reader System for Analysis and Documentation of RSID™ Tests

“…Figure 6 shows results of the RSID™ Field Kit tests for undiluted extracts of blood, saliva, semen and urine as they appear in a digital image (Nikon's Coolpix 5600) and from images taken from the RSID™ Reader. A weak Test Line signal for samples with an estimated 5.3 µL of semen is due to the High Dose Hook Effect [4], but was still scored positive by the RSID™ Reader. …”

“…Cassettes 3 and 4, on which an estimated 2.5 nL of semen were tested had very light positive signal, which was expected since 2.5 nL of semen is at the detection limit of RSID™ Semen test [4]. To measure reproducibility of RSID™ Reader, cassette 3 was analyzed three times on both RSID™ Readers.…”

“…The Rapid Stain IDentification (RSID™) Blood, Saliva, Semen and Urine Kits (Independent Forensics, Lombard, IL, USA) are lateral flow immunochromatographic strip tests designed for identifying one of four body fluids from biological residue on forensic evidence recovered from crime scenes [1][2][3][4][5]. Lateral flow tests, like the RSID™ series are widely used for screening forensic evidence.…”