What is a Hemastix?
Detection of presence of blood in urine. The Hemastix® urinalysis test strip is the reliable frontline test for detection of blood. Parameters. Blood (Urine)
What chemicals are used in Hemastix?
Substances
- Benzidines.
- Chromogenic Compounds.
- Reagent Strips.
- Phenol.
- 3,3′,5,5′-tetramethylbenzidine.
- Chloroform. DNA.
Which color is a positive result for Hemastix?
An immediate (within 5 seconds) development of a blue-green color should occur, indicating a positive result and that the reagents are operating properly. 4.3. 1 Activate a Hemastix® test square. Rub the tip of a toothpick across the questioned blood stain and then touch it to the test square.
How sensitive is Hemastix?
However during the rub test, Hemastix showed a higher sensitivity, detecting blood down to a dilution of 1:64 on porous materials while Kastle Meyer was positive only down to a dilution of 1:16.
Does Hemastix expire?
Has a shelf-life of roughly a year from the date of manufacture.
What are the 2 reagents that are used in the Hemastix test?
Hemastix®, a haemoglobin specific chemical reagent test strip (Hb-CRTS), was used with the addition of a chelating agent (EDTA) which increases the specificity of this test.
Does Hemastix destroy DNA?
Full short tandem repeat profiles were obtained from both tested and untested samples, suggesting that the Hemastix(®) reagent(s) affect DNA binding, rather than produce DNA damage. The Hemastix(®) inhibition of DNA yield could be overcome by the addition of MTL buffer to the sample prior to extraction.
Are Hemastix reliable?
Although the longevity and survival of haemoglobin on archaeological artefacts requires further investigation, the method validation described here supports Hemastix® performed with EDTA as being a reliable presumptive test for the presence of residual blood on buried artefacts.
How do you read Hemastix?
Simply rub the Hemastix on a moistened stain or across a swab that has a suspected dried blood sample on it. The reagent coated tip will turn a shade of green if hemoglobin is detected. Compare the color reaction to the chart on the side of the bottle to determine the level of hemoglobin in the sample.
What is a false positive test with Hemastix?
On the other hand, Hemastix showed a much lower specificity, producing false positive results when exposed to tomato, potato, rust, avian uric acid, bleach and sink rot, while Kastle Meyer only produced a faint positive reaction from potato.
What color is Hemastix?
The test is based on the peroxidase-like activity of hemoglobin which has the ability to cleave oxygen molecules from H2O2 and catalyzes the reaction from the reduced colorless form of 3,3′,5,5′- tetramethylbenzidine to the oxidized colored form. The resulting color ranges from orange to green.