An in vitro measurement of bleeding time.

An in vitro method of measuring the bleeding time is described. The test, called the machine bleeding time (MBT), is not affected by heparin and detects the same types of hemostatic abnormalities as the template bleeding time. It is sensitive to thrombocytopenia, aspirin administration, and von Willebrand's disease. It is a reproducible test suitable for replicate and serial determinations and permits in vitro evaluation of the addition of drugs.