ABSTRACT
Microelectrophoresis was developed in the 1950s as a method for applying pharmacologically active compounds to very limited areas of muscle or nerve cell membranes. The technique of microelectrophoresis can be easily combined with recording of intracellular or extracellular electrical activity from the cells under investigation. The electrical resistance of a micropipette depends upon many things including the physical dimensions of the micropipette, most importantly the orifice size, the concentration of the drug in solution and its degree of ionisation. The electrical resistance of micropipettes can be easily measured and therefore the voltage required to pass the desired current can be calculated by Ohm’s Law. The drug concentration at the membrane of a cell of interest will depend on many factors, including the concentration of the drug within the pipette, the electrophoretic current passed and the proportion of this current which carries the drug.
