Summary
Factors affecting the activation of factor XIII and its subsequent action in incorporating
the fluorescent amine, dansyl cadaverine, into casein have been investigated.
A comparison of the activation of factor XIII at 30° C and 37° C using 5 NIH units
Maws bovine thrombin showed that increasing the temperature shortened the time required
for maximal activity from 4-10 minutes to 4 minutes. A sharper peak of activity was
observed at the higher temperature and a more rapid fall with increasing activation
time. At 30° C, 25 units Parke Davis thrombin topical gave similar results to 5 units
Maws thrombin topical.
When an activation period of 10 minutes was selected, 5 units of thrombin gave the
highest values of factor XIII activity.
The optimal level of calcium in the incubation medium was found to be 12 mM.
