Navigation Links
Blood plasma


Blood plasma is a component of blood. It is the liquid in which blood cells are suspended. Blood plasma contains proteins, nutrients, metabolic end products, hormones, and inorganic electrolytes.

Serum is the same as blood plasma except that clotting factors (such as fibrin) have been removed.

Plasma resembles whey in appearance (transparent with a faint straw colour). It is mainly composed of water, proteins, and mineral salts. It serves as transport medium for glucose, lipids, hormones, products of metabolism, carbon dioxide and oxygen. (Oxygen transport capacity of plasma is lower compared to that of the hemoglobin in the red blood cells; it may increase under hyperbaric conditions.) It is the storage and transport medium of clotting factors and its protein content is necessary to maintain the oncotic pressure of the blood.

Laboratory use of plasma and serum

For purposes of laboratory tests, plasma is obtained from whole blood. To prevent clotting, an anticoagulant such as citrate or heparin is added to the blood specimen immediately after it is obtained. (Usually the anticoagulant is already in the evacuated blood collection tube (e.g. Vacutainer or Vacuette) when the patient is bled.) The specimen is then centrifuged to separate plasma from blood cells. Plasma can be frozen below -80°C nearly indefinitely for subsequent analysis.

For many biochemical laboratory tests, plasma and blood serum can be used interchangeably. Serum resembles plasma in composition but lacks the coagulation factors. It is obtained by letting a blood specimen clot prior to centrifugation. For this purpose, a serum-separating tube (SST) can be used which contains an inert catalyst (such as glass beads or powder) to facilitate clotting as well as a portion of gel with a density designed to sit between the liquid and cellular layers in the tube after centrifugation, making separation more convenient.

Tests of coagulation (such as the INR and APTT) require all clotting factors to be preserved. Serum, therefore, is inappropriate for these tests. A citrated evacuated blood collection tube (e.g. vacutainer or Vacuette) is usually used, as the anticoagulant effects of citrate is dependent upon concentration and can be reversed for testing.

Serum is preferred for many tests as the anticoagulants in plasma can sometimes interfere with the results. Different anticoagulants interfere with different tests; using serum means the same sample can be used for many tests. In protein electrophoresis, using plasma causes an additional band to be seen, which might be mistaken for a paraprotein.


'"/>


(Date:7/30/2014)... the way for a breakthrough that may prevent ... to poisonous chemicalsparticularly those in pesticides and chemical ... issue of the journal ChemBioChem outlines ... commonly used in pesticides and warfare agents. The ... Engineering Associate Professor of Chemical and Biological Engineering ...
(Date:7/30/2014)... truffle uses reversible epigenetic processes to regulate its genes, ... - a picture of the genome regulation taking place ... journal Genome Biology and illustrates how the ... ,jumping genes,. The authors say this may shed light ... , Black truffles (Tuber melanosporum), also known as Prigord ...
(Date:7/30/2014)... Red Queen in Lewis Carroll,s Through the Looking ... National University of Singapore improved a 35-year-old ecology ... decades to millions of years. , The new ... incorporates the "Red Queen Effect," an evolutionary hypothesis ... which suggests that organisms must constantly increase their ...
Breaking Biology News(10 mins):Engineering a protein to prevent brain damage from toxic agents 2How black truffles deal with the jumpers in their genome 2Classic Lewis Carroll character inspires new ecological model 2Classic Lewis Carroll character inspires new ecological model 3
... virus previously used as a marker in tracing human ... State. Results of this study also suggest that some ... than previously thought. , "The most genetically divergent human ... researcher at Penn State's Center for Infectious Disease Dynamics. ...
... Baptist Medical Center and colleagues at four other medical ... identify genes that may contribute to early atherosclerosis. ... and early adult life who have a genetic predisposition ... for heart disease and stroke sooner and more aggressively," ...
... In a new twist on the slogan “milk does ... staple as a contrast agent in gastrointestinal imaging exams—with ... the annual meeting of the Radiological Society of North ... bowel distension and enhancement as we see with the ...
Cached Biology News:Viral marker of human migration suspect 2Scientists work to identify genes that contribute to early heart attack risk 2Got inexpensive contrast agent? Milk plays new role in imaging 2
Other biology definitionOther Tags