1. Proteins which can be divided into distinct electrophoretic components because of the variations in their mobilities.
2. Physical and biochemical characteristics of an organism as determined by the interaction of its genetic constitution and the environment of the different proteins which are separable into distinct electrophoretic components because of the differences in mobilities.

One example is erythrocyte acid phosphatase.

The term erythrocyte refers to a blood cell that carries oxygen from the lungs to the body tissues; while, the term phosphatase is an enzyme that catalyzes the hydrolysis and synthesis of phosphoric acid esters (organic compounds that can react with water to produce an alcohol and an organic or inorganic acid) and the transfer of phosphate groups from phosphoric acid to other compounds.