Medical Conditions

Measurement of the time required by whole blood to produce a visible clot. Factors that could influence the test are all but III, VII, and XIII. Activation may be by contact with the glass tube or exposure to diatomaceous earth. Delay of onset of coagulation may be achieved by use of nonwettable plastic or silicone-coated glass tubes. It is used for monitoring heparin therapy and as a bedside screening test for deficiencies in the intrinsic coagulation pathway. "Activated coagulation time" is sometimes referred to as ACT.