Plasma
Definition
The liquid fraction of blood (approximately 55% by volume), containing water, proteins (albumin, immunoglobulins, fibrinogen, clotting factors), electrolytes, glucose, hormones, and dissolved gases. The principal source of species-specific proteins used in precipitin tests.
Related terms
- Haematocrit
- The proportion of blood volume occupied by red blood cells, approximately 45% in adult males and 40% in adult females. Influences the...
- Haemoglobin
- The iron-containing oxygen-transport protein in red blood cells, composed of four polypeptide subunits each with a haem prosthetic group. Its pseudoperoxidase activity...
- Haemolysis
- The rupture of red blood cells and release of haemoglobin into the surrounding fluid. In casework, haemolysis of aged stains, wet stains,...
- Methaemoglobin
- An oxidised form of haemoglobin in which ferrous iron (Fe2+) is converted to ferric iron (Fe3+), unable to carry oxygen. Its formation...
- Serum
- The fluid that remains after blood has clotted and the clot has been removed. It is plasma minus fibrinogen and other clotting...
Explained in
- Composition and Properties of BloodThe liquid fraction of blood (approximately 55% by volume), containing water, proteins (albumin, immunoglobulins, fibrinogen, clotting factors), electrolytes,...