The effect of activated carbon potential on the interaction of carbon with erythrocytes was investigated. A significant contribution of carbon potential in the mechanism of adsorption was elucidated via the counterintuitive observation that the maximum of erythrocyte adsorption occurred on the carbon brand with the lowest specific macropore volume, as compared with several carbons of various origins with much larger specific macropore volumes. It was observed that maximum adsorption activity of the FAS activated carbon toward erythrocyte ghosts occurs at potentials near −100 mV. Microphotographs of electrochemically modified activated carbon samples after contact with hemolyzed erythrocytes carbons showed the carbon surface covered with stained ghost cells, corroborating the electrosorption character of the interaction. This adsorption occurred exclusively in carbon macropores. It was shown that a mixture of normal-morphology erythrocytes and erythrocyte ghosts can be separated by electrosorption on electrochemically modified activated carbons.