Haematuria
Definition
The clinical term for blood in urine. Hemastix was developed as a urinalysis tool to detect haematuria and was later adopted by forensic laboratories as a rapid presumptive blood screen.
- Definition
- Blood present in urine
- Clinical origin
- Hemastix developed as a urinalysis screening tool
- Forensic adoption
- Used as a rapid presumptive blood screen
Common questions
Why did a clinical urinalysis test get repurposed for forensic bloodstain screening?+
Hemastix was designed to detect trace haemoglobin in urine cheaply and quickly using a reagent strip, and since the same peroxidase-like haemoglobin reaction underlies presumptive blood testing generally, forensic examiners adopted it as a fast, low-cost field screen for suspected bloodstains.
Does a Hemastix strip designed for haematuria work the same way on a dried bloodstain?+
The underlying chemistry is the same peroxidase-catalysed colour change, but a dried stain must first be moistened or swabbed to bring haemoglobin into contact with the reagent strip, unlike a liquid urine sample which reacts directly.
Related terms
- Bluestar
- A proprietary reformulation of luminol (brand name: Bluestar Forensic) that uses a modified buffer and reagent concentration to produce chemiluminescent detection of...
- Buffer System
- The pH-controlling salt mixture in a spray reagent. The buffer in Bluestar is designed to maintain an alkaline pH for the luminol...
- Chromogenic Pad
- The reactive zone on a Hemastix strip impregnated with a reduced chromogen (tetramethylbenzidine in some formulations) and a peroxide source. Contact with...
- Dipstick Test
- A format in which reagents are embedded in pads on a solid strip. The strip is briefly dipped into or pressed against...
- Hemastix
- A commercial peroxidase test strip (Siemens/Bayer) containing a chromogenic pad that turns blue-green on contact with haemoglobin and hydrogen peroxide. Originally designed...