Improved fibrin plate method for fibrinolytic activity measurements: use of bentonite precipitation and agar solidification.

A modification of the fibrin plate method to assure sterility and fibrin stability is described. Bovine fibrinogen is precipitated with bentonite to remove the plasminogen and agar is added to assure stability. Storage of the plates up to 7-10 days has resulted in no bacterial growth. This rapid, sensitive method is useful in the isolation of plasminogen or its activators by chromatographic separation.