[Electrophoretic mobility of antithrombin III in an agarose gel with heparin. (author's transl)]

The electrophoretic mobility of several forms of antithrombin III in an agarose gel has been compared with the mobility in a gel containing heparin. When a serum was studied, three different compounds were observed. The inactige antithrombin III with higher molecular size, separated by gel filtration, was found to be homogenous even if there was heparin in the gel. A purified antithrombin III, prepared by affinity chromatography, contained an immunoreactive material of higher molecular size which has no activity and a higher mobility in agarose gel. When heparin is incorporated in the agarose plate, the electrophoretic mobility of this polymerized antithrombin III is not modified.