ELECTROKINETIC STUDIES OF MARINE OVA. VII. RELATION BETWEEN THE ZETA POTENTIAL AND ADHESIVENESS OF THE CELL MEMBRANE OF SEA-URCHIN EGGS

Abstract

The adhesiveness of sea-urchin egg cell membranes was measured by a simple apparatus consisting of a series of tubes, square in cross section and of different dimensions, connected to a reservoir. Eggs were allowed to adhere to the glass surface, counted, and then exposed to electric currents of strengths differing according to the dimensions of the tubes. By constructing a curve of the percentages of remaining cells in different current strengths (remainder curve), the adhesiveness is expressed by the area circumscribed by the curve and the 2 axes. In Anthocidaris eggs, when the zeta potential is changed by hydrogen ions, the adhesiveness changes correlatively and the shifts in the potential and the adhesiveness are both perfectly reversible. In Strongylocentrotus pulcherrimus, both the potential and the adhesiveness change pari passu when cerium ions are added to the medium. Adhesiveness is maximum at the isoelectric point. Specific effects of individual ions play a secondary role in determining the membrane adhesiveness.