A fully automated method for clot based coagulation panels using an MCA Multistat Centrifugal Analyzer

Small modifications of the commercially available software of the I.L. Multistat Centrifugal Analyzer (MCA) enabled us to evaluate clot based prothrombin times (PT), activated partial thromboplastin times (APTT) and thrombin times (TT) simultaneously within one run. This imparted a great deal of flexibility to this procedure in that batches and/or panels of clot based and other types of turbidimetric tests can be performed concurrently in any combination. The PT and TT by this turbidimetric procedure correlated very well with those of the Fibrometer in normal specimens as well as in a wide variety of coagulation defects. The turbidimetric APTT procedure, however, often produced clotting times longer than those achieved with the Fibrometer. The discrepancy between the Fibrometer and turbidimetric APTT procedures was shown to be the consequence of greater sensitivity of the latter to detect low concentrations of heparin, elevated fibrinogen split products and mild factor deficiencies. The available clot based procedures are suitable for use in detecting specific factor deficiencies and the presence of coagulation inhibitors.