Abstract: A method for purifying two distinct insulin mediators to substantial homogeneity, and relative purity values above 80%, comprises adsorption on first anion exchange resin and subsequently on a chelex cation exchange resin column. The chelex resin ion exchange column substantially increases the activity of the recovered mediator. Following purification, the already treated fraction is subjected to three successive thin layer chromatography purification steps, the last giving, in the presence of ninhydrin stain, a characteristic salmon-color spot, which is indicative of the presence of the mediator. This process can also be used as a screening process, the absence of the salmon-colored spot being indicative of the diabetic state. Structure information on the insulin mediators obtained is given.