Abstract: A spectrophotometric assay for the detection of acetaminophen in aqueous fluids is carried out with a dry analytical element. The element comprises a support having thereon one or more reagent layers containing a first enzyme, aryl acylamidase, to cleave the amide bond of acetaminophen to produce p-aminophenol; and a mild oxidizing agent to oxidize the p-aminophenol so that it couples to a water-soluble coupling agent to form a dye that is read at 670 nm. The assay is precise, accurate on serum and plasma samples, and relatively free from significant interferences. The element also allows measurement over a broad dynamic range.

Abstract: A reaction vessel for use in a clinical analyzer includes a frame having a plurality of vertically disposed reaction chambers in spaced relation, each of the reaction chambers being sized for retaining a volume of at least one fluid. The vessel further includes at least one gap region defined between at least one adjacent pair of reaction chambers for thermally affecting the fluid contents therein.

Abstract: A method for reducing interferent bias such as hemoglobin bias in immunoassays using dried slide test elements featuring peroxidase and leuco dye as the labeling mechanism.

Abstract: A multilayer analytical element for measuring salicylate is disclosed. The element has a support. The support is coated with the following layers, top down to the support:a) a spreading layer,b) a dye layer having a pH greater than 6.5 and comprising tyrosinase and a water-insoluble hydrazone coupling agent,c) a barrier layer that prevents passage of molecules having a molecular weight in excess of 5,000, andd) a reagent layer comprising salicylate hydroxylase and nicotinamide adenine dinucleotide (NADH), wherein the spreading layer comprises valproic acid, 8-anilino-1-naphthalenesutfonic acid (ANS) or the magnesium salt of 8-anilino-1-naphthalenesulfonic acid.

Abstract: A dry multilayer element for assaying salicylate is disclosed.

Abstract: Reticulation caused by swelling with processing solutions in photographic elements is reduced for elements containing at least two contiguous gelatin-containing layers wherein the uppermost layer has a lateral swell coefficient at least 10% greater than the lower gelatin-containing layer before polymer addition and wherein said uppermost layer comprises an essentially non-diffusible vinyl polymer having reactive groups which crosslink by reaction with primary amine or secondary amine groups on gelatin or a water-soluble, non-diffusible amine containing vinyl polymer and a hardener for gelatin. These elements are particularly useful in photographic products.

Abstract: In the drying of sheet materials which have been coated with a layer, or with two or more superposed layers, of liquid coating composition, improved drying conditions which result in less formation of mottle are provided by the use of a foraminous shield, such as a screen or perforated plate, located in close proximity to the coated surface. The sheet material, for example a web of paper or polymeric film or a succession of discrete sheets of paper or polymeric film is conveyed through a drying zone, along a predetermined path, while a gaseous drying medium, such as air maintained at an elevated temperature, which serves to promote evaporation of the liquid medium in the coating composition, is directed through the foraminous shield onto the coated surface.