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Lab Test Dictionary

Platelet Aggregation (PLTAG)


Platelet Aggregometry


ADP; Arachidonic Acid

Specimen Type

Whole Blood

Performing Lab

UCSD Special Coag

Epic ID


Lab Test Days

Prescheduled (Monday-Friday

Standard TAT

24 Hours

Collection Information

Specimen Required

(three) 2.7 mL Whole Blood for Infants 5-10 kg or (five) 2.7 mL Whole Blood for Children >10kg

Container Type

Light Blue (Sodium Citrate)

Collection Instructions

Call UCSD Special Coag for inquiries, scheduling, and instructions (858) 657-5683 Monday-Friday 0800-1630 Only. FOR INPATIENTS, Main Lab must be notified prior to draw to schedule testing with UCSD Special Coag Monday-Friday 0800-1630 Only. Many drugs inhibit platelet function and can complicate proper interpretation of platelet aggregation studies. Patients should avoid all drugs for several days before testing if possible. Aspirin-containing medication should be avoided for at least 10 Days. Please have a list of medication available when calling UCSD Special Coag for scheduling. Caffein, smoking and lipemia interfere with platelet aggregation testing. Therefore, for best results, the patients should be fasting and not smoking for at least 8 hours before testing. A fat-free breakfast with no caffeine is acceptable. Collect (three-five) 2.7 mL Whole Blood in 3.2% sodium citrate (light blue-top) tubes and discard the first (light blue-top) tube. Quickly but gently mix tubes to prevent clotting. Samples must be kept at room temp at ALL times.

Processing Information - Lab Use Only

Transport Temperature


Specimen Stability

Room Temp: 3-4 Hours; Refrigerated: Unacceptable; Frozen: Unacceptable

Rejection Criteria

Hemolysis; Lipemia; NSAIDS; Salicylates; Clotted; Improper line draw

Test Volume Required

Infants 5-10 kg: (three) 2.7mL Whole Blood; Children >10 kg: (Five) 2.7 mL Whole Blood

Minimum Test Volume

Infants 5-10 kg: (three) 2.7mL Whole Blood; Children >10 kg: (five) 2.7 mL Whole Blood

Processing Instructions

Complete the UCSD Special Coag requisition and submit with specimens room temp. Specimens must be transported by "RUSH" courier to UCSD Special Coag (CALM Lab) within 1-2 Hours of collection. Samples must be kept at room temp at ALL times.


NOTE: THIS TEST IS NOT "HEPARIN INDUCED PLATELET AGGREGATION." Testing must be scheduled with UCSD Special Coag prior to specimen collection Monday-Friday 0800-1630 Only.

CPT Codes

85576 x 6