PTD - 51 

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Test Directory - Platelet Aggregation Studies



Clinical Indications

Platelet function studies may be performed if a patient has a bleeding disorder with a normal or relatively normal coagulation screen and platelet count. Typically the type of bleeding will be 'mucosal' i.e. nose bleeds, bruising, menorrhagia.

Request Form

Combined Pathology Blood form (Yellow/Black or Blue for GP's) following discussion with or requested by Consultant Haematologists.


Analysed by referral laboratory if specific criteria met.

Specific Criteria

Requested by Consultant or agreed with Consultant Haematologists

Turnaround Time

7 days


Citrated whole blood


4 x 3ml


 4 x Blue capped vacutainer tubes


Samples must be received by lab within 2 hours of collection.

Lab. Handling

Make arrangements in advance of receipt of samples with the referral lab.
Do not spin citrated samples

Causes for Rejection

Unlabelled / unsigned sample. Incorrect or inadequate patient identifiers provided. Insufficient sample volume. Poor sample quality due to deterioration, haemolysis or clot (in EDTA)


  A number of prescription and non-prescription drugs may interfere with platelet aggregation. Substances such as tobacco and alcohol may also affect test results.
Platelet count must not be less than 100,000 platelets/uL


  See individual report


See individual report



Version 1.0 / January 2013