Haem Group
Definition
The iron-porphyrin prosthetic group at the centre of haemoglobin. The iron atom cycles between oxidation states during the peroxidase-like reaction, and it is this cycling that catalyses the indicator oxidation.
Related terms
- Confirmatory Test
- A test with sufficient specificity to establish the identity of a biological fluid for reporting purposes. Examples include Takayama and Teichmann crystal...
- False Positive
- A test result that indicates the presence of a target analyte when it is absent. In forensic serology this may mean incorrectly...
- Leuco-Phenolphthalein
- The reduced, colourless form of phenolphthalein used in the Kastle-Meyer reagent. It is oxidised back to the pink quinone form in the...
- Peroxidase-Like Activity
- The catalytic behaviour of haemoglobin (and other haem-containing proteins) that mimics the enzyme peroxidase: splitting hydrogen peroxide into water and oxygen. The...
- 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,...
Explained in
- Kastle-Meyer TestThe iron-porphyrin prosthetic group at the centre of haemoglobin. The iron atom cycles between oxidation states during the peroxidase-like reaction, and it is...