When can the Ogston-Morris-Rodbard-Chrambach model be applied to gel electrophoresis?

The Ogston-Morris-Rodbard-Chrambach theory of gel electrophoresis is consis tent with predictions from the volume averaging method with respect to the equivalence of the accessible volume fraction to the ratios of gel mobility to free solution mobility and the gel diffusion coefficient to free soluti on diffusion coefficient for the limiting case of small molecule electropho resis with low electrical fields, low gel concentrations, and nonconductive gel fibers. When these conditions are not valid, more extensive calculatio ns are required to determine the mobility and diffusion coefficient ratios as functions of the geometry and electrical field within the gel. The volum e averaging theory shows that it is important to account for the electrical conductivity properties of the fibers that make up a gel electrophoresis m edium, and this aspect is consistent with early theories of transport pheno mena in gel electrophoresis.