Des-gamma-carboxyprothrombin (DCP) is a marker that appears in the blood when modifications of vitamin K-dependent proteins carboxylation cycle occur. About 280 human plasma samples of diverse origins were tested by three different electrophoretic techniques for the evaluation of DCP: rocket immunoelectrophoresis (RIE) before and after barium carbonate adsorption, crossed affinoimmunoelectrophoresis (CAIE) and polyacrylamide gel electrophoresis in presence of calcium lactate followed by immunoblotting (PAGE-blot). A good correlation was found between CAIE and PAGE-blot in the CAIE detection limit, but not between RIE and the two other techniques. PAGE-blot was more sensitive than RIE and CAIE and allowed reliable quantification of abnormal prothrombin in plasma.