Platelet count

Keywords: PLT


5 mL blood in EDTA tube.

2 mL blood in special paediatric EDTA tube.


Part of Full blood count.

Electronic counts on automated and semi-automated instruments.

Manual (microscopy) counts are not comparably accurate.

Reference Interval:

Refer to laboratory (guide only below).

150-400 x 109/L.


History of excessive and/or unusual bleeding, bruising; purpura.

Monitoring drugs with potential or predictable bone marrow toxicity.

Monitoring heparin and other drug therapy which have the potential to affect platelet count.

Post-splenectomy monitoring.

Possible Myeloproliferative neoplasms.


See Thrombocytopenia and Thrombocytosis.


Bain et al. Dacie and Lewis Practical Haematology. 11th Ed. 2012.