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.
