A technique for the electrophoretic (see electrophoresis) separation of amphoteric (i.e. able to combine with either an acid or a base) molecules in a gradient of pH, usually formed from a combination of buffers held on a polyacrylamide gel support medium. The molecules will move in the gradient, under the influence of an electric field, until they reach their isoelectric pH (i.e. the pH at which they are electrically neutral), where they form a sharp band. Separation is achieved because the various molecular species will have different isoelectric pHs.
Subjects: Chemistry — Plant Sciences and Forestry.