Abstract: In a coating method using a coating head having a coating solution supplying inlet and a slot opening, the coating solution is caused to flow from the inlet to the slot opening in such a manner that the flow width increases gradually while the flow thickness decreases gradually. An apparatus according to the invention has a coating head in which a flow path is formed between an inlet and a slot opening, such that the flow width gradually increases while the flow thickness gradually decreases.

Abstract: A method for producing gradient gel medium membrane for electrophoresis in which a monomer solution having a continuous concentration gradient and a polymerizing reaction initiator solution are supplied to a coating head as a gel forming solution for electrophoresis while mixing the monomer solution and the polymerizing reaction initiator solution with each other so as to coat a moving web with the gel forming solution. The coating liquid is supplied onto a moving web through the coating head in such a manner so that the flow of the coating liquid extends continuously in the direction of width and is continuously reduced in the direction of thickness along the coating head from its supply inlet to its slot opening.

Abstract: A method of making an electrophoresis medium having a predetermined gradient in concentrations of an acrylamide compound and a cross-linking agent comprises the steps of mixing two kinds of aqueous solutions containing the acrylamide compound and the cross-linking agent in different concentrations such that a mixing ratio of the aqueous solutions to each other is changed gradually, thereby to form a predetermined gradual change (gradient) in concentrations of the acrylamide compound and the cross-linking agent in the mixture, and carrying out cross-linking polymerization of the mixture in the presence of a polymerization initiator. Viscosity values of the two kinds of the aqueous solutions containing the acrylamide compound and the cross-linking agent in different concentrations prior to the mixing are adjusted to be substantially equal to each other.

Abstract: A process of manufacturing an element for electrophotresis which comprises steps of: sticking a spacer continuously to both side portions of a support web which is rolled back continuously from the rolled condition; casting on said support a solution for forming a medium membrane for electrophoresis; subjecting the support to hardening treatment to form a medium membrane; cutting off a portion of the medium membrane and support web; and sticking a cover sheet onto the medium membrane. An apparatus advantageously employable for performing the above process is disclosed.