Thrombotic disorders are the major causes of mortality and morbidity in Europe. Diagnostic assays, including chromogenic peptide substrate assays (CS) for thrombosis and related diseases, have led to a multi million Euro market for kits for the measurement of these factors. Despite the knowledge that blood cells play a major role in thrombosis, all of the CS assays are performed using plasma. It is very probable that a large majority of the thrombotic risk factors not identified in plasma (60%) are associated with cellular elements of blood. The aim of the project is to develop novel CS assays to measure thrombotic risk factors in whole blood. The project will lead to the production of diagnostic kits for routine hospital laboratory assays as well as "bed-side" or even "home-use” single tute or "Clinistick"-type tests. The commercial possibilities for these assays are enormous, and it is probable that the project will lead to major break through in thrombosis diagnosis.