Abstract: A composition, method and test device for determining the presence of leukocytes, esterase or protease in a test sample are disclosed. The composition comprises an ester which is hydrolyzed in the presence of leukocyte, esterase, or protease to form a reaction product which couples with a diazonium salt to produce a detectable color change. The composition further comprises the salt of an alkaline earth metal which stabilizes the composition during manufacture and prevents the occurrence of false or background color change due to reactivity of the diazonium salt in the absence of leukocyte, esterase or protease.

Abstract: A stable test device capable of manufacture by automated methods for the determination of chloride in an aqueous fluid sample. The test device operates by controlled diffusion of the aqueous sample into a porous matrix. The matrix is incorporated with sodium carrageenan and silver salts capable of dissolving in an aqueous fluid containing chloride, at least part of which silver salts is silver chromate. Devices prepared with the inclusion of sodium carrageenan provide a chloride test device with approximately double the shelf life under room temperature storage conditions of previous test devices prepared without sodium carrageenan. The stable test device provides useful information in less than about 2 minutes after the sample contacts the matrix. The chloride concentration of the sample is determined by comparing the pattern of silver chromate remaining after sample contact to an appropriate pattern chart.

Abstract: Improved test compositions, devices and methods are provided for detecting peroxidatively active substances in body fluids, body excreta and the like. The test compositions include an indicator or chromogen capable of being oxidized in the presence of a peroxidatively active substance to provide a color change, an oxidizing agent effective to oxidize said indicator or chromogen, and as a potentiating agent capable of enhancing the color obtained, a compound of the formula: ##STR1## wherein R.sub.1 is hydrogen, a lower alkyl group of 1 to 4 carbon atoms or hydroxy, and R.sub.2, R.sub.3 and R.sub.4 are independently selected from hydrogen or a lower alkyl group of 1 to 4 carbon atoms; provided that at most only one R group is substituted.