Laboratory tests for platelet disorders may include: Assessing platelet number and size [MPV] Assessing platelet morphology – blood film Screening tests of platelet function e.g. Activated Clotting Time [ACT], Bleeding Time [BT] and PFA-100 Light Transmission Aggregometry e.g. classical Born aggregometry Assessment of platelet nucleotides Flow cytometry e.g. to quantitate the presence or absence of platelet membrane glycoproteins