PROTHROMBIN TIMES AND CLOTTABLE FIBRINOGEN DETERMINATIONS ON AN AUTOMATED COAGULATION LABORATORY (ACL 810) ANALYZER.

The ACL 810 is a fully automated, microcomputer controlled centrifugal analyzer (Instrumentation Laboratory/IL). It performs clot based and chromogenic substrate assays. The clot based assay utilizes laser nephelometry. Prothrombin times (PT) in normal and abnormal plasmas were analyzed on the ACL using different thromboplastins and the data compared with a Fibrometer and a Coag-A-Mate. The correlation between the ACL (II reagents) and the Coag-A-Mate and Fibrometer (Thromboplastin C, Dade) for 100 samples were as follows: ACL vs Coag-A-Mate r = 0.87 (p < 0.001), m (slope) 1.13; ACL vs Fibrometer r = 0.92 (p < 0.001), m = 1.1.

Since the ACL 810 determines PT and fibrinogen simultaneously, we compared fibrinogen levels on the ACL 810 (II Thromboplastin) with those analyzed on a Multistat III Centrifugal Analyzer (MCA) (bovine thrombin, Hemostasis Laboratories) and a Fibrometer (Data-Fi, Dade). The following correlations were obtained: ACL vs Fibrometer n = 50, r = 0.922 (p < 0.001), m 0.72; ACL vs MCA n = 100, r 0.899 (p < 0.001), m 0.7; MCA vs Fibrometer n = 70, r = 0.954 (p < 0.001), m = 0.936. We also compared different manufacturers' thromboplastins on the ACL 810 in the determination of fibrinogen with the following results:

The run-to-run coefficient of variation (CV) for fibrinogen was 4.4% and for PT 0.26%; the intra-run CV was 4.66% and 0.41%. These data reveal excellent correlations for both PT and fibrinogen not only with different instruments but also with different thromboplastins on the same instrument.