noun, plural: sera, serums
(1) The clear portion of any bodily fluid
(2) Blood serum: the clear liquid devoid of the clotting factors
In general, the serum pertains to the clear portion of any bodily fluid, of an animal or a plant. For instance, the animal serous (or serosal) fluid is the fluid secreted by serous glands.
In blood, the serum is the clear, pale-yellow liquid derived from the blood and is devoid of blood cells and clotting factors. Blood plasma is the fluid component of the blood and where the blood cells are suspended. The plasma in which the clotting factors are removed is the blood serum.
An antiserum or an immune serum is a serum with specific antibodies (naturally or artificially produced). It is used medically for administering passive immunity to certain diseases.
Word origin: Latin serum (“whey”)
- serumal (adjective, of, relating to, pertaining to, or characterized by serum)