Forensic medicine – MCQ 47 – Hydrogen peroxide in blood tests

Hydrogen peroxide is used in all of the following chemical tests for blood except:
A. Benzidine test
B. Phenophthalein test
C. Orthotolidine test
D. Teichmann’s test

Correct answer : D. Teichmann’s test

Benzidine test, phenolphthalein test, orthotolidine test and Leucomalachite green test utilise hydrogen peroxide to detect presence of blood. Hemoglobin present in blood is a peroxidase. It oxidises colourless bases to coloured salts in the presence of hydrogen peroxide.

Teichmann’s test (haemin crystal test) is done by converting haemoglobin to haemin crystals which is converted to salt in the presence of halogen and forms rhombic crystals.