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Make heterogeneous electron transfer fast relative to delivery of reactant, usually by applying sufficient overpotential so that its surface concentration approaches zero. Use excess supporting electrolyte to suppress migration. For purely diffusional transient transport, suppress uncontrolled convection; for a rotating disk electrode, controlled convection supplies the bulk while diffusion across the thin interfacial boundary layer limits the current. A limiting current that no longer increases with driving potential is the characteristic test; a large current alone is not sufficient.

A supporting electrolyte is an electrolyte added at a concentration high compared with that of the electroactive analyte. Its ions carry much of the solution electric current, reducing the electric-field-driven migration of the analyte.

The chosen electrolyte should not undergo appreciable interfering electrode reactions in the potential range being studied. It still affects ionic strength and interfacial conditions, so supporting-electrolyte identity is part of an electrochemical measurement's conditions.