CAPABILITIES AND POTENTIALITIES OF TRANSVERSE PORE GRADIENT GEL-ELECTROPHORESIS

Transverse pore gradient gel electrophoresis is important as a tool fo r obtaining nonlinear Ferguson plots [log(mobility) vs. gel concentrat ion], e.g. in application to DNA in polyacrylamide gels or to agarose gels, with the purpose of evaluating molecular properties (size, confo rmation, malleability) and gel fiber properties (fiber radius and leng th per unit volume). To date, it is capable of (i) yielding gel patter ns (''Ferguson curves'') of migration distance vs. predicted %T-range of the pore gradient, assuming its linearity;(ii) yielding information regarding molecular conformation from the intersection of Ferguson cu rves of unknowns (e.g. bent DNA) with those of standards; (iii) acquis ition of Ferguson curves by computer, using prototype instrumentation; (iv) mathematical manipulation of acquired Ferguson curves to yieldin g Ferguson plots, providing that mobility in free solution has been as sessed by capillary zone electrophoresis. The potentialities of the me thod remain unfulfilled to date due to (i) the unavailability, with a single exception, of an accurate and precise way to produce pore gradi ents of known shape; (ii) unavailability of a routinely applicable ana lysis for %T; (iii) unavailability of optimized, user-friendly and foo lproof instrumentation for computer acquisition of Ferguson curves, in cluding the present inapplicability of a commercially available electr ophoresis apparatus with intermittent optical detection to transverse pore gradient gels; and (iv) unresolved problems in the statistical ev aluation of Ferguson curves.