Clinical chemistry the denser blood cells and platelets to the bottom of the centrifuge tube, leaving the liquid serum fraction resting above the packed cells. This initial step before analysis has recently been included in instruments that operate on the "integrated system" principle. Plasma is in essence the same as serum, but is obtained by centrifuging the blood "without" clotting. Plasma is obtained by centrifugation "before" clotting occurs. The type of test required dictates what type of sample is used. A large medical laboratory will accept samples for up to about 700 different kinds of tests. Even the largest of laboratories rarely
Dilute Russell's viper venom time specificity than the aPTT test for the detection of lupus anticoagulant, because it is not influenced by deficiencies or inhibitors of clotting factors VIII, IX or XI as the venom only activates factors V and X. Variations in the test can affect the results. The dRVVT is one component of a workup of a suspected antiphospholipid antibody, the other component being the serological testing for anticardiolipin antibodies and anti-β2 glycoprotein-I antibodies using ELISA technology. The Sapporo criteria require at least one of the above laboratory tests to be positive and the patient to have at least one clinical manifestation of