RSID Strips (Independent Forensics)
Definition
Lateral-flow immunochromatographic strips for confirmatory identification of blood (glycophorin A), semen (semenogelin I), saliva (salivary amylase), urine (urea transporter UT-A), vaginal fluid (cornulin), and menstrual blood (MMP-10).
- Manufacturer
- Independent Forensics
- Blood target
- Glycophorin A
- Semen target
- Semenogelin I
- Saliva target
- Salivary amylase
- Vaginal fluid target
- Cornulin
Common questions
Why does each RSID strip use a different protein target?+
Blood, semen, saliva, urine, vaginal fluid, and menstrual blood each contain a protein produced predominantly or specifically by that tissue type, such as glycophorin A on red blood cells or cornulin in vaginal epithelium, so targeting that protein confirms the fluid rather than merely detecting a general biological reaction.
How reliable is the vaginal fluid strip compared to older glycogen-based tests?+
The cornulin-based RSID assay is protein-specific to vaginal epithelial cells, giving it higher specificity than older glycogenated-cell staining methods, which can be confounded by cell types found in other body sites.
Are RSID strips used on the same swab as DNA extraction?+
Typically an aliquot of the extract, or a portion of the stain, is tested with the strip before or alongside DNA processing, since the strip result guides how the remaining sample is interpreted without consuming all of the evidentiary material.
Related terms
- ABAcard P30
- A lateral-flow immunochromatographic strip manufactured by Abacus Diagnostics and validated by the Scientific Working Group for DNA Analysis Methods (SWGDAM) for forensic...
- Confirmatory Test
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- Kastle-Meyer (KM) Test
- Phenolphthalein-based colorimetric presumptive blood test relying on haem peroxidase activity. Positive result: pink colour within 2-5 seconds of hydrogen peroxide addition.
- Luminol
- A chemiluminescent reagent (5-amino-2,3-dihydro-1,4-phthalazinedione) that produces blue-white light on contact with haemoglobin-derived iron. Detects blood diluted to 1:10,000,000 or more. Used as...
- mRNA Profiling
- Detection of messenger RNA transcripts specific to particular tissues or body fluids. Endometrial-specific transcripts (LEFTY2, MMP-10 mRNA, others) can distinguish menstrual blood...
- Presumptive Test
- A fast, low-cost, class-specific screen used to triage a caseload before instrumental work begins. Examples are Marquis reagent for opioids and amphetamines,...