Level of Protein C Determined by Combined Assays During Disseminated

We have developed a variation of the solid-phase enzymelinked immunosorbent assay (ELISA) to enable measurement of the activity and antigen levels of protein C (PC) in human plasma. With this assay it is possible to do both tests with the same sample and same microtiter plate coated with anti-PC monoclonal antibody (MCA)JTC-4, which inhibited neither activation of PC nor activity of activated PC (APC). Even in patients undergoing heparin treatment for severe disseminated intravascular coagulation, there were no detectable differences between amidolytic activity and antigen levels of PC in patients’ plasma. In addition. there was a strong correlation between the immunologic levels of PC in patients’ plasma determined both by polyclonal ELISA using peroxidase-labeled immu-