Se"rum (sē"rŭm), n. [L.,
akin to Gr. ???, Skr. sāra curd.] (Physiol.)
(a) The watery portion of certain animal fluids,
as blood, milk, etc. (b) A thin watery
fluid, containing more or less albumin, secreted by the serous
membranes of the body, such as the pericardium and
peritoneum.
Blood serum, the pale yellowish fluid which
exudes from the clot formed in the coagulation of the blood; the
liquid portion of the blood, after removal of the blood corpuscles and
the fibrin. -- Muscle serum, the thin
watery fluid which separates from the muscles after coagulation of the
muscle plasma; the watery portion of the plasma. See Muscle
plasma, under Plasma. -- Serum
albumin (Physiol. Chem.), an albuminous body,
closely related to egg albumin, present in nearly all serous fluids;
esp., the albumin of blood serum. -- Serum
globulin (Physiol. Chem.), paraglobulin. --
Serum of milk (Physiol. Chem.), the whey,
or fluid portion of milk, remaining after removal of the casein and
fat.