What type of test is Hemastix?

• A. A confirmatory test for blood
• B. A DNA typing test
• C. A presumptive test for blood
• D. A quantitative test for blood

Answer: (C)

Hemastix is a quick colorimetric strip test that uses the peroxidase activity of hemoglobin to produce a color change. Because it detects this enzymatic activity, it can indicate that blood may be present on a surface, but it does not prove that the substance is blood nor identify where it came from. This makes it a presumptive test—useful for rapid screening, but not definitive. It also doesn’t quantify how much blood is present, nor does it provide any information about the donor or the blood’s origin. To move from a putative indication to a confirmed identification, more specific confirmatory tests are required, often involving chemical or immunological methods that can verify the presence of blood—and sometimes its source—beyond peroxidase activity. Hemastix is not a DNA typing test, which would reveal genetic information, nor is it a quantitative measure of blood amount; those capabilities require different analytic approaches.