Specimen Collection Manual and Test Catalog

TWO 2 mL 3.2% sodium citrate blue-top tubes are required for each test.

Collect ONLY at hospital location. A specimen cannot be sent via courier.

Collect TWO sodium citrate tubes. Draw this tube prior to any other anticoagulant or additive tubes. Walk tube to laboratory (do not send via pneumatic tube).

Perform venipuncture with no trauma. If blood is drawn from indwelling catheter, flush with 5 mL of saline and discard the first 5 mL of blood collected to avoid contaminating sample with tissue thromboplastin or heparin. If using a butterfly needle setup for collection, draw a discard blue-top tube first to remove air from tubing. Specimen must be collected with a needle diameter no smaller than a 21 gauge. 

Test is offered at a limited number of performing laboratories and may only be collected and performed at testing sites (see below). Send blood specimen to lab as soon as possible after collection.

If also drawing ASPIRIN, VERIFYNOW, specimen needs to be drawn in TWO separate tubes.

Do NOT centrifuge. Uncentrifuged whole blood at room temperature required for analysis. Walk specimen to laboratory.

Room temperature.

4 hours.

Overfilled tube, underfilled tube, stability limit exceeded, tube system use, sent via courier, centrifugation of whole blood, HCT >55%, and other sizes or vendors' 3.2% sodium citrate tubes.

182-335 PRU (P2Y12 reaction units)

Effective drug use will manifest in a reading of PRU below the normal range. Results lower than the low reference range (182) are highly specific for a P2Y12 Inhibitor effect. If the sample was drawn 12 hours after administration of the medication, a normal PRU test will be observed based on validation studies. Resistance is seen in a small number of patients and will manifest as a normal value with appropriate drug usage confirmed.

Plavix, InhibP

Plavix test, PFPLAV, VERIFY P2Y12

Clopidogrel (Plavix) or similar drugs are anticoagulants used in patients with cardiovascular disease that block ADP induced platelet activation via the P2Y12 platelet receptor. The anticoagulants may cause prolonged surgical bleeding or bleeding associated with trauma.