Automation of plasma antithrombin III assays

We have developed automated assays for antithrombin III for use with the Gilford 3500 and the Multistat Microcentrifugal Analyzer. The assays are two-stage kinetic-rate methods and involve use of human thrombin and the chromogenic peptide substrate S-2238. The reagents are prepared in-house from commercially available components. Both automated methods have good precision and results correlate well with both an established chromogenic substrate assay and an immunological assay. The automated assays offer the advantages of speed, sensitivity, high throughput, and low reagent consumption and are useful for both routine work and high-volume testing in clinical studies and screening programs.