PURPOSE: To improve resolving power and a handling property from a practical aspect, by constituting an electrophoretic medium layer by containing alkyl sulfate and other surfactant in a predetermined acrylamide aqueous gel.
CONSTITUTION: A polyacrylamide gel membrane is formed on a plastic sheet comprising a hydrophilic polymer or a sheet of which the surface is made hydrophilic as an electrophoretic medium layer. Said gel membrane is obtained by forming an aqueous solution or dispersion containing an acrylamide compound and a crosslinking agent into an aqueous gel membrane by crosslinking polymerization. Alkyl sulfate ion surfactant and other surfactant are contained in said gel membrane. The content of the alkyl sulfate ion surfactant as a modifier is set to about 0.05W2.0w/v%, pref., about 0.1W1.5w/v% to the gel forming liquid. The content of the other surfactant is 1×10-4W5×10-1w/v%, pref., 1×10-3W5×10-2w/v% per a volume of the electrophoretic medium layer.
OGAWA MASASHI
KATO TAKESHI
