osocza

Osocze, in Polish, refers to the liquid portion of blood that remains after the blood has clotted. In English, this substance is called serum. It is the extracellular fluid that contains water, electrolytes, nutrients, hormones, and waste products, along with various proteins, but it lacks most clotting factors such as fibrinogen.

Compared with plasma, osocze does not contain the clotting factors that are present in blood plasma. Osocze is obtained by allowing a blood sample to clot and then separating the liquid by centrifugation.

Proteins in osocze include albumin and immunoglobulins; it also carries enzymes, antibodies, metabolites, and hormones. The exact composition can reflect physiological conditions and may vary with health status, age, diet, and the handling and timing of sample collection.

Clinical use: Osocze is widely employed in laboratory diagnostics for serology, immunology, and biochemical testing. It is suitable for antibody detection, hormone and metabolite assays, and many immunoassays. It is not used for blood transfusion because it lacks fibrinogen and other clotting factors present in plasma.

Notes: Hemolysis or improper handling can affect osocze results, and care is taken to avoid contamination that might alter tests.

Etymology: The term osocze is Polish; in international usage the equivalent term is serum.