| plasmacrit | A measure of the percentage of the volume of blood occupied by plasma, in contrast to a haematocrit. Origin: plasma + G. Krino, to separate (05 Mar 2000) |
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| plasmacrit test | A serologic screening method used as an aid in the diagnosis of syphilis; after only a few drops of heparinised blood (obtained from a pricked finger) are collected in a special capillary tube, the capillary tube is centrifugated in order to collect plasma, which is then mixed with a 0.01-ml drop of antigen (cardiolipin previously treated with choline chloride as an anti-inhibitor, in order to avoid falsely negative results that may occur with nonheated plasma or serum). After mechanically agitating the antigen-plasma mixture for 4 min, the presence or absence of flocculation is observed. A positive result should not be regarded as conclusively diagnostic, but a negative result excludes the likelihood of syphilis. (05 Mar 2000) |