Abstract: The invention provides a nonenzymatic method useful for the semiquantitative determination of glucose, a test composition and test device. Glucose concentration in an aqueous test sample can be determined by preparing a test solution by contacting an aqueous test sample and a dihydroxide component, at an initial pH above 6.5, capable of forming a complex with glucose which complex formation releases a proton, and determining the final pH of the test solution. The invention also provides a self-indicating device format which allows the determination of glucose concentration by merely counting the number of pads which have changed color. No comparison to a color chart is required. The glucose test of the present invention is free of the interferences found in enzymatic glucose tests.

Abstract: A method for detecting blood analytes with a sample volume as low as 2 microliters in the hematocrit range of 0% to 60%, or higher. This is accomplished by using a diagnostic device comprising a housing with various chambers and compartments for processing the blood. A sample application port in the housing is used to introduce blood into a metering chamber. From the metering chamber, the blood flows to a reaction chamber for analyzing blood analytes. Blood entering the metering chamber flows into a fluid capillary which indicates that an adequate amount of blood has been received in the metering chamber. The reaction compartment includes a reagent and a filter, the latter of which is disposed between the metering chamber and the reagent so that the reagent reacts with the filtered blood.

Abstract: A conductive sensor and its use in a diagnostic assay are disclosed. The miniaturized conductive sensor, utilizing a conducting polymer, is used in a diagnostic device to determine the presence or concentration of a predetermined analyte in a liquid test sample, wherein the predetermined analyte, like glucose, is assayed by an oxidase interaction. The interaction between the oxidase and a small amount of the predetermined analyte in the test sample generates, either directly or indirectly, a dopant compound in a reaction zone of the conductive sensor. The dopant compound then migrates to the detection zone of the conductive sensor of the diagnostic device to oxidize the conducting polymer and convert the conducting polymer from an insulating form to a conducting form. The resulting increase in conductivity of the conducting polymer is measured, then the conductivity increase is correlated to the concentration of the predetermined analyte in the test sample.

Abstract: A method and composition for the assay for albumin at an essentially neutral to an alkaline pH. The method utilizes indicator dyes that, when sufficiently buffered in a pH range of approximately 6 to approximately 8, allows the detection of albumin in urine or serum. The indicator dyes utilized in the method of the present invention have the general formula: ##STR1## wherein R.sub.1 and R.sub.2 are substituted aromatic heterocyclic or carbocyclic moieties having one or more electron-withdrawing functionalities present on the aromatic ring; R.sub.3 is a substituted aromatic heterocyclic or carbocyclic moiety having one or more electron-withdrawing functionalities present on the aromatic ring, or R.sub.3 is a non-aromatic electron-withdrawing moiety; R.sub.4 is a substituted quasi-aromatic quinone-like heterocyclic or carbocyclic moiety having one or more electron-withdrawing functionalities present on the quasi-aromatic quinone-like ring; and R.sub.

Abstract: A composition, test device and method of determining the presence or concentration of ketone bodies, and specifically D-.beta.-hydroxybutyrate, in a test sample are disclosed. The test device includes a test pad comprising a suitable carrier matrix incorporating an indicator reagent composition capable of interacting with D-.beta.-hydroxybutyrate to produce a detectable or measurable response. In addition, a new and improved indicator reagent composition, comprising a) an indicator dye that is responsive to thiols, such as a substituted isobenzothiazolone, Ellman's reagent or a derivative of Ellman's reagent; b) D-.beta.-hydroxybutyrate dehydrogenase; c) lipoamide dehydrogenase; d) D,L-lipoamide; and e) nicotinamide adenine dinucleotide, is incorporated into the carrier matrix to provide an accurate and sensitive assay of a test sample for D-.beta.-hydroxybutyrate (DHBA) in particular, and for ketone bodies in general.

Abstract: A spectral cover for a reflectance photometer is disclosed in which the spectral cover is designed to cover the readhead area of the reflectance photometer and block the transmission of light in a wavelength range of at least 60 to no more than 200 nanometers centered about the detection wavelength while permitting light of other wavelengths to be transmitted. The invention permits the readhead cover to be permanently or semipermanently positioned on the reflectance photometer. Since a user is able to see through the spectral cover it is possible to position a test device correctly and quickly over the readhead of the reflectance photometer. Signal noise levels due to ambient light are substantially eliminated by the invention.

Abstract: A process for measuring the presence or appearance of thiols in aqueous system, the process involving contacting the aqueous system with a chromogenic thiol indicating benzoisothiazolone derivative and then observing chromophoric changes due to thiol mediated reduction of the benzoisothiazolone derivative wherein the changes are proportional to the amount or rate of appearance of the thiols in the aqueous system.

Abstract: The present invention provides a novel group of protein error indicators including nitro or nitroso substituent groups in the B and C rings of a partially halogenated triphenylmethane compound.

Abstract: The present invention relates to a chromogenic benzoisothiazolone polymer derivative for measuring the presence or appearance of thiols in an aqueous system.

Abstract: A method and composition for the enzymatic assay of a liquid test sample, such as urine or serum, for a specific analyte, such as glucose. The method utilizes a dry phase test strip comprising a carrier matrix impregnated with a stabilized enzyme reagent composition including an oxidase enzyme, such as glucose oxidase, that is capable of interacting with the analyte of interest; a chromogen that changes color in response to the analyte-oxidase enzyme interaction to reveal the presence and/or concentration of the analyte in the test sample; and a stabilizer, such as a hydrazide, like GIRARD'S Reagent T, or an amino acid, like arginine, or an amino acid derivative, like the tris(hydroxymethyl)aminomethane sale of glutamic acid, to improve the heat stability and shelf life of the dry phase test strip.

Abstract: A radiation aperture system where two sets of apertures are distributed in ring sections of like radius on two parallel rings. As one ring is rotated with respect to its counterpart, one aperture of each ring will align to pass a radiation beam through both apertures. Only a single aperture pair is formed at each unique time, allowing sequential measurements of all combinations of both aperture openings during rotation without halting the rotation.

Abstract: A reagent strip calibration system utilizes an electrical connection system particularly usable for making electrical connections to one-time use devices such as reagent strips. The connection employs a plurality of U-shaped contacts fabricated from a hard metal wire such as tungsten, beryllium copper or a nickel/iron alloy that is self-supporting or supported by an elastomer that also provides contact pressure between the wire and the one-time use device while providing low insertion force. Such a connection system is particularly suitable for use with a system for analyzing the chemical properties of an analyte that is placed on a reagent strip. The manner in which the chemical properties of the reagent strip are to be analyzed are defined by areas of different resistance disposed on the reagent strip and contacted by the U-shaped contacts to permit measurement of the resistance of the various areas to obtain the information needed to define the properties of the reagent strip.

Abstract: A diagnostic device detects blood analytes with a sample volume as low as 2 microliters in the hematocrit range of 0% to 60%, or higher. This is accomplished by employing a housing with various chambers and compartments for processing the blood. A sample application port in the housing is used to introduce blood into a metering chamber. From the metering chamber, the blood flows to a reaction chamber for analyzing blood analytes. Blood entering the metering chamber flows into a fluid capillary which indicates that an adequate amount of blood has been received in the metering chamber. The reaction compartment includes a reagent and a filter, the latter of which is disposed between the metering chamber and the reagent so that the reagent reacts with the filtered blood.

Abstract: This invention relates to a device and a method for measuring the specific gravity of liquids, in particular, urine. This invention more particularly concerns a component of an automated system for urinalysis, either of humans or animals. The device may also be developed as a stand-alone unit and includes a dispenser, a sample container in which the liquid is dispensed and flushed, and a fiber optic sensor system to record the refractive index of the liquid. The invention is particularly suited for use with small clinical samples.

Abstract: Compositions and test articles comprisng ionophore of an optically active isomer of bis(12-crown-4-methyl)dialkyl malonate, wherein alkyl group is methyl and the second alkyl group has 4 to 20 carbon atoms, with a reporter substance incorporated in a hydrophobic carrier are disclosed.