Factor VII Antigen

Factor VII Quantitation (Nonfunctional)

11 days

Enzyme-linked immunosorbent assay (ELISA)

60–175%

Accredited Laboratory Partner

This test is used to measure the level of factor VII antigen in plasma.

Plasma

1 mL

Blue-top (sodium citrate) tube

Do not draw from an arm with a heparin lock or heparinized catheter.

Blood should be collected in a blue-top tube containing 3.2% buffered sodium citrate.14 Evacuated collection tubes must be filled to completion to ensure a proper blood-to-anticoagulant ratio.15,16 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 unless the sample is collected using a winged (butterfly) collection system. With a winged blood collection set, a discard tube should be drawn first to account for the dead space of the tubing and prevent under-filling of the evacuated tube.17,18 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 alternative 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.

Please print and use the Volume Guide for Coagulation Testing to ensure proper draw volume.