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 5mL of saline and discard the first 10 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. Send blood specimen to lab as soon as possible after collection.

If also drawing P2Y12 INHIBITOR REACTIVITY (CLOPIDOGREL), 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, refrigeration of whole blood, HCT >55%, and other sizes or vendors' 3.2% sodium citrate tubes.

>= 550 ARU (aspirin reaction units).

>= 550 ARUs indicates no evidence of platelet dysfunction due to Aspirin. <550 ARUs indicates platelet dysfunction consistent with Aspirin effect.

Aspirin, VerifyNow

Aspirin test, % Inhibition of aspirin, PFASA

Aspirin is used to irreversibly inhibit the platelet enzyme cyclo-oxgenase (COX-1) and block the thromboxane A2 pathway, ultimately preventing platelet aggregation and prolonging patient bleeding. The effect of aspirin lasts while the platelets are in circulation.