ABSTRACT
Over the past 40 years a fairly wide variety of techniques have been employed to assay the intracellular pH, and until quite recently there was little effort to obtain more than an average value for the whole cell. It was only several years ago that advanced techniques of Nuclear magnetic resonance spectroscopy and of dual-excitation fluorescence shed more light on the local pH variation within the cell. Conceptually most straightforward, but technically very exacting, is the method using pH-sensitive electrodes small enough to penetrate into single cells without damaging them. Most of these microelectrodes are simply miniature versions of the long-known and long-used glass electrode made of a “pH sensitive” glass. Besides using glass pH-sensitive electrodes, attempts were made in the past to use an antimony electrode where the antimony tip is covered with a thin layer of Sb(III) oxide.
