Haemichrome
Definition
A further oxidation product formed when the globin chains of methaemoglobin denature and the haem group becomes internally coordinated. Associated with the darker brown-to-black colour of older stains.
Related terms
- Methaemoglobin
- An oxidised form of haemoglobin in which ferrous iron (Fe2+) is converted to ferric iron (Fe3+), unable to carry oxygen. Its formation...
- Oxyhaemoglobin
- The form of haemoglobin in freshly shed arterial blood, where iron in the haem group is in the ferrous (Fe²⁺) state and...
- Photodegradation
- Breakdown of biological molecules driven by ultraviolet and visible radiation. In bloodstains it accelerates haemoglobin oxidation and cleaves DNA strands, hastening ageing...
- Protein Denaturation
- The loss of a protein's three-dimensional structure without breaking peptide bonds, caused by heat, pH change, UV radiation, or chemical agents such...
- Substrate Effect
- The influence of the surface on which a bloodstain lies on the rate and character of chemical change. Porous substrates absorb blood...
Explained in
- Physical and Chemical Changes in Ageing BloodstainsA further oxidation product formed when the globin chains of methaemoglobin denature and the haem group becomes internally coordinated. Associated with the dar...