The KCT is a sensitive screening test of lupus anticoagulants (LA) in patients with a history of thrombosis.
Specimen Type
Blood
Container
Blue Top Tube
Collection Instructions
Container/Tube: Light Blue tube 3.2 % buffered sodium citrate Specimen: 1 ml citrated plasma( 0.5 mL min) Transport Temperature: Frozen Collection Citrated plasma samples should be collected by double centrifugation. Blood should be collected in a blue-top tube containing 3.2% buffered sodium citrate. Evacuated collection tubes must be filled to completion to ensure a proper blood-to-anticoagulant ratio. The sample should be mixed immediately by gentle inversion at least six times to ensure adequate mixing of the anticoagulant with the blood. A discard tube is not required prior to collection of coagulation samples except when using a winged blood collection device (ie, "butterfly"), in which case a discard tube should be used. When noncitrate tubes are collected for other tests, collect sterile and nonadditive (red-top) tubes prior to citrate (blue-top) tubes. Any tube containing an alternate anticoagulant should be collected after the blue-top tube. Gel-barrier tubes and serum tubes with clot initiators should also be collected after the citrate tubes. Centrifuge and carefully remove the plasma using a plastic transfer pipette, being careful not to disturb the cells.
Transport Instructions
Frozen
Specimen Stability
4 hours Room Temperature 7 Days Frozen
Methodology
Clot In the kaolin clotting time (KCT) test, kaolin, a negatively-charged particulate activator, is incubated with test plasma to activate the contact factors and the intrinsic system. Calcium chloride is added and the mixture is timed until a clot forms.
