A measure of the concentration of erythrocytes in the blood. An average figure for humans is 45%, i.e. a packed red cell volume of 45 mL in 100 mL of blood. Usually measured by centrifuging heparinized blood in a capillary tube or by using a cell analyser which will give cell numbers and volumes from which the haematocrit can be calculated.
Subjects: Medicine and Health — Chemistry.