Some effects of pH and formaldehyde on the cellular electrokinetic surface.

Abstract

AbstractWhen the electrophoretic mobilities of many cells are measured in solutions having pH values in excess of 9, or after formaldehyde‐fixation, there is an increase in their net surface negativity which is usually attributed to deprotonation of amino‐groups at the cell surface. A detailed investigation of the effects of high environmental pH and formaldehyde treatment on cell electrophoretic mobility suggests that the mobility changes are largely due to the adsorption of released intracellular contents to the cell surface and that, contrary to current belief, information obtained by experiments of this type may not be interpreted to indicate the presence of positively‐charged groups at the electrokinetic surfaces of intact living cells.