Chromogenic Activity Assay
Used to identify and quantitate a Protein C defect or deficiency in those patients subject to recurrent venous thrombosis or pulmonary emboli.
80 - 150%
The presence of Factor V Leiden may lead to lower protein C values. This methodology detects the amidolytically active portion of the activated protein C, including the non-carboxylated molecules synthesized in vitamin K deficiency. Thus, in conditions of vitamin K deficiency, a higher protein C activity is found with chromogenic Protein C than when using a coagulometric method.
- PROTEIN C ACTIVITY
Collect specimen in a blue top (citrate 3.2%) tube. Mix by inversion. Specimen should arrive at lab within 3 hours of collection; transport at room temperature. Alternatively, centrifuge, aliquot plasma into a plastic vial, and freeze the specimen within 4 hours of collection. Transport frozen specimen on dry ice. Collection of the blood through lines that have been previously flushed with heparin should be avoided. If the blood must be drawn through a VAD (vascular access device), the line should be flushed with 5 mL of saline and the first 5 mL of blood or six dead space volumes of the VAD discarded.