Imperial Collage Healthcare

PFA-100 (Platelet Function Analysis)

Test Background

Platelet function is initially assessed using the PFA-100 analyser which offers quantitative assessment of platelet function at high shear as whole blood is forced through an aperture coated with either collagen/epinephrine or collagen/ADP agonists. The test is measured as aperture closure time (CT) in seconds for each COL/EPI and COL/ADP cartridge.

The PFA is sensitive to platelet function defects such as Glanzmann’s Thrombasthaenia and Bernard-Soulier Syndrome as well as disorders of von Willebrand factor, though sensitivity is reduced when VWD Type I is included. Aspirin or aspirin-like platelet defects are associated with a significantly prolonged COL/EPI closure time.

Clinical Indications

Investigation of bleeding phenotype suggestive of possible platelet function disorder
Confirmation of previously diagnosed platelet function disorder

Reference Range

Closure Times



Sample Required
4.5 mL sodium citrate (pale blue top) adults 1.8 mL sodium citrate (pale blue top) paediatrics

Turnaround Time
4 hours


Please note: Samples will be rejected if under/over-filled, clotted or haemolysed

Please do not send samples via pod system

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