Simple Non-gassing Electrodes for Use in Electrophoresis

Abstract

THE electrodes conventionally used in electrophoresis are noble metal (usually platinum), metal/metal ion (for example, Cu/Cu²⁺) and metal/insoluble metal salt (for example, Ag/AgGl/Cl⁻). With the last two types the apparatus must be provided with convection barriers to prevent metal ions in the electrode compartments from contaminating the experimental material. Platinum electrodes, even if platinized, permit only a limited current density (less than 2 m.amp./cm.²) without giving an evolution of gas bubbles which disturbs the observations in closed electrophoresis systems such as are used in the moving boundary and microscopic methods. We wish to describe here the general conditions under which palladium–hydrogen electrodes can be used to provide adequate current densities for electrophoresis without gassing or danger of contamination from heavy metals.