Relation of Blood Thromboplastin Activity to Its Total Phospholipid Content.

Abstract
(1) The amount of total phospholipid in blood thromboplastin was found to correlate with thromboplastic activity. (2). A sufficient concentration of the total phospholipid in formed thromboplastin appears to be critical. However, the mere presence of phospholipid does not insure strong thromboplastic activity. (3) There was no relation between amount of total phospholipid in the precursor substances, either before or after centrifugation, and total phospholipid in the blood thromboplastin. This strongly suggests that active changes occur during thromboplastin formation.