Abstract: A method for the purification and recovery of cholesterol oxidase is disclosed. Cholesterol oxidase is purified by a method including the steps of:(a) contacting a solution of the cholesterol oxidase to be purified with a chromatography composition comprising an unbound water-insoluble steroid which is a nonsubstrate for cholesterol oxidase so as to adsorb the cholesterol oxidase on the steroid;(b) separating the solution from the steroid; and(c) contacting the steroid with an eluting solution containing a surfactant at a concentration between 0.001 percent and 10 percent so as to recover the adsorbed cholesterol oxidase.In a preferred embodiment, the solution containing the cholesterol oxidase to be purified is a microorganism growth medium having cholesterol oxidase activity and, prior to the step of contacting the solution with a steroid, the solution is contacted with an ion-exchange chromatography material.

Abstract: An element for the analysis or transport of liquid, especially aqueous liquids, contains a structure comprising a plurality of heat-stable, organo-polymeric particles non-swellable in and impermeable to the liquid, and an adhesive concentrated at particle surface areas contiguous to adjacent particles bonding the particles into a coherent, three-dimensional lattice that is non-swellable in the liquid. A substantial portion of the particle surface area in this lattice structure is therefore effectively free from adhesive. The lattice structure has interconnected void spaces among the particles representing a total void volume of about 25 to 80 percent to provide for transport of the liquid. The adhesive comprises an organic polymer different from that of the particles and insoluble in the liquid under analysis. The amount of adhesive in the structure is less than 10 weight percent of the particles.

Abstract: Direct-positive photographic emulsions and elements which include internal-image silver halide grains, a nucleating amount of a hydrazine compound and a redox dye releaser are improved by the incorporation of a nucleation-promoting amount of a quinone oxidizing agent. Diffusion transfer images made from elements using these emulsions exhibit improved image discrimination and improved maximum density.