Return to Test Directory
Test Mnemonic:


Specimen Requirements:





Four (4) blue-topped (3.2% sodium-citrate) tubes and one (1) purple-topped tube. Needle size should be between 19 and 21 gauge.

Routine venipuncture; discard 1st mL of blood or collect other tubes (EDTA, red-topped) prior to collecting sample tubes. Immedately invert tubes gently at least 4 times to mix



Blue-topped (3.2% sodium-citrate) tube


Sample should be stored at room temperature. Do not refrigerate or freeze specimen (platelet are activated at cold temperature).

Specimen Preparation:

Specimen must be delivered to the laboratory within 1 hour of collection. Always be handled at room temperature (20-25°C) before testing and should never be refrigerated or chilled on ice or frozen.


Stable at room temperature for 3-4 hours.

Causes for Rejection:

Underfilled tubes, clotted, improperly collected samples, thrombocytopenia with platelet count <100 x 103/ul, severe hemolysis or lipmeia, samples received in the laboratory after 1 hour of collection.

Reference Range:

Final Aggregation % is report for each agonist tested

ADP 20 uM:                                         58 – 100%       

ADP   2 uM:                                           9 – 100%

Arachidonic Acid (AA) 0.5 mM       54 – 94%

Collagen 190 ug/ml:                          55 – 98%

Epinephrine 10 uM:                          52 – 100%

Ristocetin 1.5 mg/ml:                      55 – 99%

Ristocetin 0.5 mg/ml:                        0 – 6%

Risotcetin 0.25 mg/ml:                     0 – 4%


Turnaround Time:

24 - 48 hours


Photo Optical Detection


Must be scheduled with Hematology/ Coagulation Laboratory at 409-772-2293. Performed on Day Shift only, Monday through Friday.



Clinical Indication:

Differentiates Platelet functional status and abnormalities, based on platelet response tp Arachidonic acid, ADP, Collagen, Epinephrine, and Ristocetin

Patient Preparation :

Prior to drawing sample, patient must be fasting fast for eight (8) hours and must not have taken aspirin or medications containin aspirin within the previous 7-10 days (contact lab for medication list). Physician must provide a list of medications that the patient has taken

CPT 4 Code:

 85576 x5


If applicable, state clinical information that is required to be provided with specimen.

When ordering tests for which Medicare or Medicaid reimbursement will be sought, physicians should only order tests that are medically necessary for the diagnosis or treatment of the patient. Components of the organ or disease panels may be ordered individually. The diagnostic information must substantiate all tests ordered and must be in the form of an ICD-10 code or its verbal equivalent.
Return to Test Directory