Summary
1. A method for the separation from clotting factors and the concentration of an inhibitor
of intermediate product I present in adsorbed plasma and adsorbed serum is described.
2. This inhibitor is not only stable but also activated at 37° C. At 4° C it loses
activity.
3. The inhibitory effect on the formation of intermediate product I is counteracted
by small amounts of prothrombin or thrombin.
4. After addition of inhibitor prothrombin is necessary for the formation of intermediate
product I in the purified system.
5. The discrepancy, in regard to the need for prothrombin (or thrombin) between the
purified and the non-purified system can be explained by the relative amounts of inhibitor
in the two systems.
