Buffy coat

Buffy coat

The buffy coat is the fraction of an anticoagulated blood sample after density gradient centrifugation that contains most of the white blood cells and platelets.

Description

After centrifugation, one can distinguish a layer of clear fluid (the plasma), a layer of red fluid containing most of the red blood cells, and a thin layer in between, making up less than 1% of the total volume of the blood sample, the buffy coat (so-called because it is usually buff in hue), with most of the white blood cells and platelets. The buffy coat is used, for example, to extract DNA from the blood of mammals (since mammalian red blood cells are anucleate and do not contain DNA).

The buffy coat is usually whitish in color but sometimes green, if the blood sample contains large amounts of neutrophils, which are high in green myeloperoxidase.

Diagnostic Uses of the Buffy Coat

*Quantitative Buffy Coat (QBC) is a laboratory test to detect infection with malaria or other blood parasites: the blood is taken in a QBC capillary tube which is coated with acridine orange (a fluorescent dye) and centrifuged; the fluorescing parasites can then be observed under ultraviolet light at the interface between red blood cells and buffy coat. This test is more sensitive than the conventional thick smear and in >90% of cases, the species of parasite can also be identified.
*In cases of extremely low white blood cell count, it may be difficult to perform a manual differential of the various types of white cells, and it may be virtually impossible to obtain an automated differential. In such cases the medical technologist may obtain a buffy coat, from which a blood smear is made. This smear contains a much higher number of white blood cells than whole blood.

References


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Look at other dictionaries:

  • Buffy coat — Composants du sang après centrifugation. Le Buffy Coat est la fraction d un échantillon de sang non coagulé après centrifugation qui contient la plupart des globules blancs et des plaquettes. Description Après centrifugation du sang, 3 couches… …   Wikipédia en Français

  • Buffy coat — Buffy Buff y, a. (Med.) Resembling, or characterized by, buff. [1913 Webster] {Buffy coat}, the coagulated plasma of blood when the red corpuscles have so settled out that the coagulum appears nearly colorless. This is common in diseased… …   The Collaborative International Dictionary of English

  • buffy coat — bəf ē n the superficial layer of yellowish or buff coagulated plasma from which the red corpuscles have settled out in slowly coagulated blood * * * the thin yellowish layer of leukocytes overlying the packed red cells in centrifuged blood;… …   Medical dictionary

  • Buffy-Coat — Zentrifugierte Blutprobe Der Buffy Coat (engl. buff: lederfarben, coat: Schicht, Film), im deutschen gelegentlich als Leukozytenfilm bezeichnet, ist die Grenzschicht zwischen roten Blutkörperchen und dem Blutplasma, die entsteht, wenn man Blut… …   Deutsch Wikipedia

  • Buffy coat — zentrifugierte Blutprobe Der Buffy Coat (engl. buff: lederfarben, coat: Schicht, Film), im deutschen gelegentlich als Leukozytenfilm bezeichnet, ist die Grenzschicht zwischen roten Blutkörperchen und dem Blutplasma, die entsteht, wenn man Blut… …   Deutsch Wikipedia

  • buffy coat — noun : the superficial layer of yellowish or buff coagulated plasma from which the red corpuscles have settled out in slowly coagulated blood * * * Biochem. a yellowish white layer consisting of leukocytes that, upon centrifugation of blood,… …   Useful english dictionary

  • buffy coat method — (for detecting Leishmania, microfilariae, and trypanosomes) a blood sample is centrifuged in a hematocrit tube and the buffy coat is examined for parasites …   Medical dictionary

  • buffy coat — Thin yellow white layer of leucocytes on top of the mass of red cells when whole blood is centrifuged …   Dictionary of molecular biology

  • buffy coat — Biochem. a yellowish white layer consisting of leukocytes that, upon centrifugation of blood, covers the red blood cells. [1790 1800] * * * …   Universalium

  • buffy coat —    The whitish layer of cells (white blood cells plus platelets) overlaying the red cell pellet after centrifugation of whole blood …   Forensic science glossary

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