Sign in →

Test Code VN Plt ASA VerifyNow Platelet Inhibition Aspirin Assay

Important Note

Lab phlebotomists do not draw this test on patients <4 years of age. Specimen requirements for this test lead to a high rate of unsuccessful collections on patients younger than 4 years. Please contact laboratory medical director, Dr. Wayne Chandler (x7-2314), with questions.


Do not use tube system to transport samples. Do not agitate samples. Collect blood sample using a 21 gauge needle or larger. Butterfly needles (21 gauge) are ok to use.  Testing must be performed with in 2 hours.

Clinical System Name

VerifyNow Platelet Inhibition Aspirin Assay


 Verify Now


Results could be affected by the following: GPIIb/IIIa inhibitors, low HCT, low PLT or inherited platelet disorders. Patients with HCT<20% or PLT<50 K/uL cannot be tested with the VerifyNow Assay.

Sample Requirements

Specimen: Whole blood

Container(s): 2 Greiner Citrate Tubes-obtain from Core Coag Lab x72561

Preferred Vol: 2 mL in each tube

Minimum Vol:  n/a


Note: Do NOT use tube system to transport samples, must be hand carried to the laboratory. Do not agitate the sample. Testing must be performed with in 2 hours of collection. Sample cannot be used for any other testing


Line draws are not recommended for this test.  Lab phlebotomists will not draw patients <4 years of age due to the difficulty in obtaining appropriate samples from this population. Ordering providers may contact Laboratory medical director Dr. Wayne Chandler with questions.


Samples should be collected between 2 and 30 hours after ingestion of aspirin to show drug effect.


Lab:   Greiner Citrate tube kits are located in Core Coag Lab x72561



Processing Instructions

Reject due to: Improper tubes, agitating samples, hemolysis.

Spin: N

Aliquot: N

Temp: RT

Storage location: Coag storage tracking.


Note: Deliver blood to CORE coag bench. Coag Technologist will process.


Off-site collection: Cannot be collected outside Children's.


Specimen Type Temperature Time

Whole blood

Greiner Citrate Tubes

Room temp 2 h
  Refrigerated N
  Frozen N



STAT Performed TAT
N Daily 1 d


Performing Laboratory

Seattle Children's Laboratory


Reference Range



≤ 550 ARU




Method:  VerifyNow System

Analytical Volume:


Limitations: Method is affected by  improper handling. Do not use tube system to transport samples. Do not agitate samples, testing must be performed with in 2 hours.


CPT Codes