Summary
Plasmas collected with Trasylol and EACA were studied for fibrin formation in the ethanol gelation and protamine sulfate tests. The latter test was difficult to read and a solid gel was rarely found, even when a definite solid gel was apparent in the ethanol gelation method. The protamine sulfate test is also said to record split products of fibrin. However, if hirudin was added to mixtures of plasma and fibrin digestion products, protamine sulfate did not cause gel formation, indicating that thrombin (or formation of thrombin) was necessary also for the gel formation induced by split products.
The protamine sulfate and ethanol gelation tests have several limitations. Care should be taken to avoid uncritical interpretations of results obtained with these tests.
