Abstract: The present invention is a method for the detection of creatinine in an aqueous solution, particularly urine, which involves contacting the solution with a soluble cupric salt, a hydroperoxide and an oxidizable indicator which provides a detectable response in the presence of oxygen free radicals and a pseudoperoxidase. The invention is predicated on the discovery that cupric ions form a complex with creatinine which complex exhibits peroxidase like activity.

Abstract: Disclosed are a method and device for performing sequential analytical reactions involving a first dry reagent and a second dry reagent comprised of two or more components having different rates of solubilization. The invention enables one to fully solubilize the components of the second reagent before they are brought into contact with each other to thereby avoid interference with the reaction kinetics which result when one or both of the components are not fully dissolved prior to their being brought into contact. The invention is especially useful in conjunction with immunoassay formats involving latex bound antibodies and polymeric agglutinators.

Abstract: A method for the presumptive detection of Candida in vaginal fluid, thereby providing an aid to the diagnosis of Candida vaginosis. A sample of vaginal fluid is combined with a test composition comprising an indicator system that provides a chromogenic response in the presence of D-arabinitol; the detection of an elevated level of D-arabinitol indicating the presumptive presence of Candida. The test composition preferably comprises the enzyme D-arabinitol dehydrogenase, NAD, an electron transfer agent, and a chromogenic indicator.

Abstract: Disclosed is an improved procedure for the manufacture of a diagnostic test device comprising a matrix having uniformly dispersed a tetrazolium salt and a reagent system designed to convert the tetrazolium to its colored formazan upon contacting the matrix with a fluid containing an analyte whose presence and/or concentration is being sought. The procedure involves applying the tetrazolium salt to the matrix from its solution in an organic solvent and, after drying, applying the reagent system to the matrix from its aqueous solution to which has been added hexanesulfonate as wetting agent.

Abstract: 2-Thiazolyl tetrazolium salt compounds characterized by a reflectance spectrum exhibiting an extended plateau above about 600-650 nm. Such compounds are useful as chromogenic indicators for reducing substances such as NADH. The reflectance plateau confers improved accuracy to analytical assays, particularly for the determination of analytes of medical diagnostic significance, in which a colorimetric response on a reagent carrier matrix is measured by reflectance.

Abstract: Disclosed are arylazo chromoionophores characterized by the formula: ##STR1## wherein X is hydrogen or a monovalent cation, Y is H or methoxy and R is a ringed aromatic organic structure which affects the optical absorption properties of the compounds. Also disclosed is a method for the detection of calcium ion using these compounds.

Abstract: 2-Benzothiazolyl tetrazolium salt compounds have been found to be characterized by a reflectance spectrum exhibiting an extended plateau above about 600-650 nm. Such compounds are useful as chromogenic indicators for reducing substances such as NADH. The reflectance plateau confers improved accuracy to analytical assays, particularly for the determination of analytes of medical diagnostic significance, in which a colorimetric response on a reagent carrier matrix is measured by reflectance.

Abstract: Phenyl substituted 2-thiazolyl tetrazolium salt compounds characterized by a reflectance spectrum exhibiting an extended plateau above about 600-650 nm. Such compounds are useful as chromogenic indicators for reducing substances such as NADH. The reflectance plateau confers improved accuracy to analytical assays, particularly for the determination of analytes of medical diagnostic significance, in which a colorimetric response on a reagent carrier matrix is measured by reflectance.

Abstract: A method for separating high density lipoproteins from blood serum or plasma. The method involves contacting the blood sample with an absorbant material comprising porous silica or silicate to adsorb the high density lipoprotein in preference to other lipoproteins in the blood sample. When combined with means for removing very low density lipoproteins and chylomicrons from the blood sample, the remaining low density lipoproteins can be measured directly.

Abstract: Methods for blood sample preparation using reagent compositions which include a zwitterionic surfactant for sphering of cells to eliminate orientational noise. When the reagent composition including a for staining a subset of cells is reacted with an anticoagulated blood sample, and the reaction mixture is passed through the sensing region of a flow cytometer, the light scattered and absorbed by each cell is measured, the stained cells can be distinguished from the unstained cells, and when the cells are reticulocytes and mature erythrocytes, respectively, the volume and hemoglobin concentration of each reticulocyte or erythrocyte, and the hemoglobin content, mean cell volume, mean corpuscular hemoglobin concentration, and mean cell hemoglobin of the reticulocytes or erythrocytes are calculated from the measured cell-by-cell volume and hemoglobin concentration.

Abstract: A layered device suitable for use in the analysis of blood samples which includes a first layer of a matrix material having dispersed therein a complex of copper and a polymer containing multiple pendant carboxyl groups which selectively combines with hemoglobin and bilirubin in fluid communication with a second layer which contains a reagent system which reacts with one or more predetermined analytes in the blood sample to provide a color change.

Abstract: A high-precision liquid reagent delivery system is provided for convenient and efficient gravity flow delivery of substantially the entire volume of reagent contained within a sealed formed tray. The delivery system comprises a formed tray defining a curved cavity for holding a predetermined amount of liquid, and a substantially planar ledge surface defined around the cavity opening. The surfaces of the cavity are non-porous, uniform and smoothly converging to a point of liquid discharge at an intersection of the cavity and the ledge surface. The ledge surface further defines an apex extending longitudinally from the point of liquid discharge and defines a guide path for the delivery of liquid contained within the tray. The system also includes a flexible cover removably affixed to the ledge surface of the tray for forming a sealed chamber between the cavity and the affixed cover for containment of liquid.

Abstract: Use of a lithium salt, particularly lithium thiocyanate, as an agent for lysing red blood cells and denaturing hemoglobin in the performance of an immunoassay to detect the relative amount of a hemoglobin derivative in a blood sample. The method is particularly useful in the determination of hemoglobin Alc. The method provides a rapid means for releasing hemoglobin from red blood cells by lysis and for exposing the epitope that is characteristic of the Alc form. Low concentrations of the lithium salt provide rapid release and denaturation of hemoglobin without the need for dilution prior to the performance of the immunoassay.

Abstract: Disclosed is a cleaning composition for hard surfaces which comprises an aqueous solution of an acidic or basic cleaner, a surfactant together with a silicone glycol and xanthan gum as anti-fogging agents.

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: An automated diabetes data interpretation method is provided which combines symbolic and numeric computing approaches in order to identify and highlight key clinical findings in the patient's self-recorded diabetes data. The patient data, including blood glucose levels and insulin dosage levels, recorded by a diabetic patient over a period of time by means of a glucose meter or the like, is initially downloaded into a central processing system such as a personal computer.

Abstract: Disclosed are sulfonate and phosphonate salts of tetrazolium compounds whose enhanced solubility in various solvents renders them particularly suitable for use as redox indicators in dry reagent, diagnostic test systems.

Abstract: Disclosed is a method for separating biological substances, particularly hemoglobin or bilirubin, from blood plasma or serum which involves contacting the plasma or serum with a water insoluble complex of a polymer containing multiple pendant carboxyl groups and copper.

Abstract: Disclosed is a novel diagnostic reagent system for the detection of hydroperoxides or substances which react with peroxidatively active substances resulting in the liberation of hydroperoxides which reagent system comprises a chromogenic oxidation indicator and a peroxidase or a peroxidatively active substance, together with an inhibitor of color generation selected from the group of 1,4-disubstituted semicarbazides, thiosemicarbazides and 1,5-disubstituted carbazides as inhibitors of color generation. By inhibiting the generation of color formed by oxidation of the chromogenic indicator, the indicator's usefulness in discriminating between varying concentrations of analyte is enhanced.

Abstract: Electrically conducting homo- and/or copolymers and/or tripolymers can be produced from novel monomers, such as a 3-substituted 2,5-di(2-thienyl)pyrrole. The polymers exhibit unexpectedly high stability and conductivities, and can be functionalized, such as with an enzyme, like glucose oxidase, or an ion-specific binding site, like a crown ether, or an antigen, without adversely affecting the conductivity of the polymer. The functionalized, conducting polymer can be used in a diagnostic device to determine the presence and concentration of a specific analyte in a liquid medium.