Abstract: The present invention provides a process for the detection of redox reactions by introducing a redox reagent system into a test system, wherein a soluble iodate is additionally added to the test system in an amount which is in excess of the highest amount of disturbing reducing agents present in the test system.The present invention also provides a diagnostic agent for the detection of redox reactions containing a redox reagent system, wherein the test system used additionally contains an iodate which is soluble therein in an amount which is in excess of the highest amount of disturbing reducing agents present in the test system.

Abstract: A guaiac reagent-based diagnostic aid for determining the presence of occult blood in an aqueous system contains a micron-sized silica gel into which a guaiac solution has been adsorbed. The guaiac-containing carrier is contacted with a dry, particulate, oxidizing agent, such as a monopersulfate compound, to form a single composition. This composition can be packaged in a water-pervious sandwich. Upon contact with water, the oxidizing agent is activated to produce hydrogen peroxide, which in the presence of occult blood will oxidize the adsorbed guaiac to a brilliant blue reaction product.

Abstract: A dry analytical element for use in detecting a specific component contained in a liquid, which element comprises one or more water permeable layers provided on a water impermeable support, at least one layer of the water-permeable layers containing a composition capable of interacting with said specific component contained in said liquid. The composition contains a leuco dye and a dispersion containing said leuco dye is incorporated in the water-permeable layer, which is formed by dissolving the leuco dye in a hydrophobic solvent containing an aliphatic higher alcohol and dispersing the resulting solution in a hydrophilic medium. The leuco dye has the formula: ##STR1## where R.sup.1 represents an unsubstituted or substituted aryl group, R.sup.2 represents an unsubstituted or substituted alkyl group, and R.sup.3 represents an unsubstituted or substituted aryl group. A process for producing said dry analytical element is also disclosed.

Abstract: A new and improved test device and method of determining the presence and concentration of fructosamines in a test sample. The test device includes a test pad comprising a carrier matrix incorporating an indicator reagent composition capable of interacting with fructosamines to produce a detectable or measurable response. The carrier matrix of the device includes a bibulous matrix, such as filter paper, or a nonbibulous matrix, such as a polymeric film. In addition, a new and improved indicator reagent composition comprising a dye, such as tetrazolium violet; a suitable buffer; and an accelerator compound is incorporated into the carrier matrix to provide a test pad demonstrating sufficient color resolution and having sufficient sensitivity to fructosamines in a test sample. Therefore, a fast, more accurate and trustworthy fructosamine assay of a liquid test sample, such as whole blood or serum, is achieved.

Abstract: The present invention is directed to an agent and method for eliminating ascorbate interference in reagent systems, particularly assay systems using oxidase/peroxidase coupled reactions or similar type redox chemistry. The present invention can also be used in reagent systems involving enzyme/substrate reactions in which the substrate is sensitive to reductants such as ascorbate. The agents of this invention comprise water insoluble cerium (IV) compounds.

Abstract: Fecal occult blood tests of enhanced sensitivity, specificity, and readability are provided by employing (1) a developer or complete reagent solution that uses as a solvent system a solvent comprising at least about 50% by volume of a solvent for iron protoporphyrins such as dimethyl sulfoxide and/or (2) a multi-chromagen comprised of a mixture of guaiac and ABTS. Test results may be further improved by incorporating hemoprotein solubilizing agents, plant peroxidase inhibitors, iron/copper chelating agents, accelerators and buffers in the developer/reagent.

Abstract: An improved method for detecting peroxidatively active materials in a sample is provided, the method incorporating antimalarial drugs such as quinine, quinidine, chloroquine, primaquine, and quinacrine as modulating compounds. In a preferred embodiment, the method is a fecal occult blood test (FOBT), in which a fecal specimen is contacted with a chromogen and a hydroperoxide in the presence of a selected quinoline derivative. The method enables careful modulation of test sensitivity and specificity, and further provides an FOBT in which interference from dietary meat ingestion is substantially eliminated.

Abstract: A dry analytical element having functional layers which contain dehydrogenase, oxidized nicotinamide coenzyme, pyruvate, an electron transport compound and an electron acceptable dye-forming compound is disclosed. The improvement the analytical element resides in that the coenzyme and dye-forming compound are contained in one or two layers which are different from a layer containing pyruvate.

Abstract: Fecal occult blood tests of enhanced sensitivity, specificity, and readability are provided by employing (1) a developer or complete reagent solution that uses as a solvent system a solvent comprising at least about 50% by volume of a solvent for iron protoporphyrins such as dimethyl sulfoxide and/or (2) a multi-chromagen comprised of a mixture of guaiac and ABTS. Test results may be further improved by incorporating hemoprotein solubilizing agents, plant peroxidase inhibitors, iron/copper chelating agents, accelerators and buffers in the developer/reagent.

Abstract: A peroxide-testing method using a reagent based on Ti(IV) compounds which contains, in a lower aliphatic alcohol having 1-5 C atoms, a compound TiX.sub.4 in which X is Cl or OR with R being an alkyl group having 1-5 C atoms, and where appropriate, up to 35% by weight of an acid which has a pK.sub.a value not exceeding 5. The method is useful for the determination of peroxides in both aqueous and organic solutions since the reagent is miscible with the sample solution to produce a homogeneous phase.

Abstract: Test devices are disclosed which are useful for determining glucose or occult blood comprising a carrier matrix, glucose oxidase, an indicator system and a glucose derivative that upon addition of water hydrolizes to produce glucose.

Abstract: An agent for the detection of peroxidase or of pseudoperoxidase activity, and its preparation and its use are described. The agent contains a tetraalkylbenzidine, a penicillin, or its breakdown products obtained by acid hydrolysis, as stabilizer,a peroxide and buffer substances. The agent according to the invention has, as a peroxidase substrate, the advantage over previous tetraalkylbenzidine-containing substrates that it is stable on storage as solution for use, and produces a lower background coloration.

Abstract: It is known that chromogenic materials which yield a color reaction when in the presence of a peroxide of the formula ROOR' which decomposes to yield ROR' and oxygen are unstable when in the form of working solutions for use in chromogenic reactions. Such compositions which also contain the peroxide required for such reactions are also unstable, leading to premature appearance of color. Stable chemical compositions are disclosed herein containing chromogenic materials and containing mixtures of chromogenic materials and peroxides, which can be used in chromogenic reactions after having been stored for long periods of time. Stabilizing chemical compositions and methods are also disclosed for obtaining such stable compositions.

Abstract: The interference of dehydroascorbic acid, an oxidation product of ascorbic acid, in analytical methods is reduced with the use of certain nitrogen-containing organic buffers. Dehydroascorbic acid tends to cause premature reduction of reducible compounds which are used to provide detectable species in the presence of an analyte. These organic buffers, as opposed to inorganic buffers, prevent premature reduction of the reducible compounds. An analytical method can be carried out in solution or in a dry analytical element.

Abstract: Devices and methods are provided for making a plurality of determinations of the local (site-specific) redox state of a liquid system, by employing a photoresponsive element, which can be independently irradiated at different sites to provide independently detectable signals.

Abstract: Certain methanol soluble ortho-benzo or -naphthoquinones are useful electron transfer agents. They are particularly useful in the detection of cells in urine.

Abstract: A method for the determination of peroxide in a sample is disclosed which comprises reacting the peroxide with a chromogen represented by the general formula (I) or (II) ##STR1## wherein R.sub.1 and R.sub.3 represent amino, mono- or di- substituted amino, hydroxyl or hydroxyalkyl, R.sub.4 and R.sub.5 represent hydrogen, alkyl, alkylene, acyl, halogen, sulphone, nitro, carboxyl, hydroxyl or hydroxyalkyl, R.sub.2 represents hydrogen, ##STR2## wherein R.sub.6 represents hydrogen, alkyl, aralkyl, alkylene, aryl or mono- or di- substituted aryl, and --Z-- may change to --Z.dbd. by resonance and represents --S--, --O--, --N.dbd., ##STR3## wherein R.sub.7, R.sub.8, R.sub.9 and R.sub.10 have the same significance as R.sub.6 in the presence of heme compound, iodide or bromide and measuring the absorbancy of the reaction solution in the visible ray region.

Abstract: Devices and methods are provided for making a plurality of determinations of the local (site-specific) redox state of a liquid system, by employing a photoresponsive element, which can be independently irradiated at different sites to provide independently detectable signals.

Abstract: The present invention discloses an assay for nucleic acid which comprises the steps of;(a) providing a probe material comprising;(i) a sequence of nucleic acids complementary to a given target sequence and,(ii) a first ligand chemically linked thereto and capable of a specific binding reaction with an antiligand;(b) contacting the said probe material with an assay system comprising:(i) a suitable mediator, enzyme, substrate system capable of transferring charge to an electrode surface when the enzyme is catalytically active, and;(ii) a second ligand chemically linked to one of said mediator, enzyme or substrate, wherein the second ligand is capable of a competitive binding reaction with the antiligand, and;(iii) the said antiligand, Whereby the said first ligand competes with the said second ligand in a specific binding reaction with the antiligand, and;(c) contacting the above system with a solution suspected of containing the said target sequence whereby the binding of any of the said target sequence presen

Abstract: Electrochemical detection of mediator level is employed in a method of assay using a redox enzyme and redox substrate to detect conversion to an effective mediator by an assay enzyme label of a compound which is non-mediating under the assay conditions.

Abstract: Fecal occult blood tests of enhanced sensitivity, specificity, and readability are provided by employing (1) a developer or complete reagent solution that uses as a solvent system a solvent comprising at least about 50% by volume of a solvent for iron protoporphyrins such as dimethyl sulfoxide and/or (2) a multi-chromogen comprised of a mixture of guaiac and ABTS. Test results may be further improved by incorporating hemoprotein solubilizing agents, plant peroxidase inhibitors, iron/copper chelating agents, accelerators and buffers in the developer/reagent.

Abstract: Fecal occult blood tests of enhanced sensitivity, specificity, and readability are provided by employing (1) a developer or complete reagent solution that uses as a solvent system a solvent comprising at least about 50% by volume of a solvent for iron protoporphyrins such as dimethyl sulfoxide and/or (2) a multi-chromogen comprised of a mixture of guaiac and ABTS. Test results may be further improved by incorporating hemoprotein solubilizing agents, plant peroxidase inhibitors, iron/copper chelating agents, accelerators and buffers in the developer/reagent.

Abstract: A method and test composition for colorimetrically determining hydrogen peroxide in a sample includes a chromogen of the formula: ##STR1## which is reacted with hydrogen peroxide in the sample in the presence of peroxidase. The absorbancy of the reaction solution is then measured.

Abstract: Certain reducible aromatic and quinone compounds having bulky groups on the carbamate nitrogen atom have improved stability to light. These compounds are useful in analytical compositions, elements and methods, e.g. for assays of bacterial cells. These compounds have suitable substituents that promote the release of phenalenone or benzphenalenone fluorescent dyes at physiological pH.

Abstract: A method and slide for collecting and testing fecal occult blood which permits multiple analyses of a single fecal sample. The slide contains a pocket-like member on a portion of the inside front cover of the slide. An absorbent insert is disposed in the pocket. When the cover is in a closed position the pocket overlies the fecal smear on the specimen viewing sheet and the insert can be removed from the pocket. This design permits an analysis to be done on the specimen receiving sheet of the slide together with a second confirmatory test on the insert.

Abstract: Ethyl alcohol test strip fabricating and use techniques for testing an individual's saliva to determine his sobriety are disclosed. The test strips employ an alcohol oxidase, Peroxidase and an hydrogen donor indicator such as Tetraalkylbenzidine in a carrier matrix supported on the strip with the alcohol oxidase functioning as a catalyst to convert any ethanol present along with ambient oxygen to acetaldehyde and hydrogen peroxide. The peroxidase function as catalyst to induce a color change in the hydrogen donor and convert the hydrogen peroxide to water. The method of fabricating the test strip involves multiple steps of reagent application and hot air drying.

Abstract: The invention comprises a method for determining the corrosion rate of metals in contact with a liquid system which is capable of causing corrosion of such metals which comprises adding to the liquid system an electrochemically active compound having a reduction potential more positive than the metal in contact with the liquid system and then monitoring the system thus treated with the electrochemically active compound to determine its rate of reduction which is proportional to the corrosion rate of the metal.

Abstract: A stable test device for the determination of a peroxidatively active substance comprising a carrier containing 1,4-diisopropylbenzene dihydroperoxide and a benzidine indicator in a molar ratio of from 0.9 to 3.0. The composition can be incorporated in a carrier matrix along with a ferric chelate to provide ascorbate resistance thereto, which is important in a urine test for occult blood. The test device is stable under storage and heat stress and can be used to prepare a multitest strip containing a glucose test based on a peroxidase/potassium iodide indicator system.

Abstract: Certain substituted benzo- and naphthoquinone electron transfer agents are useful in analytical compositions, elements and methods, e.g. for determinations of living cells. These electron transfer agents are capable of being reduced by an analyte, and the reduced electron transfer agent, in turn, reduces another compound providing a detectable species (e.g. a dye). The reduction potential (E.sub.1/2) of the electron transfer agents useful inthis invention is in the range of from about -320 to about +400 mV as measured in an aqueous buffer solution at pH 7.

Abstract: The present invention provides a process for the detection of redox reactions by introducing a redox reagent system into a test system, wherein a soluble iodate is additionally added to the test system in an amount which is in excess of the highest amount of disturbing reducing agents present in the test system.The present invention also provides a diagnostic agent for the detection of redox reactions containing a redox reagent system, wherein the test system used additionally contains an iodate which is soluble therein in an amount which is in excess of the highest amount of disturbing reducing agents present in the test system.

Abstract: The present invention provides a method for assaying a biocomponent on the basis of an amount of bound peroxidase by the steps of supporting a biocomponent or a target substance containing a biocomponent on a gel-like carrier, developing the biocomponent or the target substance by electrophoresis, binding a receptor to the biocomponent or the target substance, binding peroxidase to the receptor, and determining the amount of the bound peroxidase, wherein hydrogen peroxide and 4-methoxy-1-naphthol are used as substrates.

Abstract: The present invention provides N-acylidihydroresorufin derivatives of the general formula: ##STR1## wherein R.sup.1 is a lower alkyl, aryl or aralkyl radical, which can be substituted by carboxyl or sulphonic acid residues, R.sup.2, R.sup.3 and R.sup.4, which can be the same or different, are hydrogen or halogen atoms or lower alkyl or lower alkoxy radicals, Y is an --NR.sup.5 R.sup.6 or --OR.sup.7 group, wherein R.sup.5 and R.sup.6 are, in each case, hydrogen atoms or lower alkyl radicals, which can be substituted by carboxyl or sulphonic acid residues, or together represent a hydrocarbon bridge optionally interrupted by hereto atoms and R.sup.7 is a lower alkyl radical which can be substituted by a lower alkoxy or poly-lower alkoxy radical.

Abstract: An analytical method for the determination of hydrogen peroxide utilizes a hydrazide or a hydrazine substituted with one or more electron withdrawing groups. The hydrazides or hydrazines react with phenolic color couplers in the presence of hydrogen peroxide and a peroxidative compound to form a dye detectable at a wavelength of 600 nm or greater. These materials can also be used to assay analytes, such as glucose and cholesterol, which can react to produce hydrogen peroxide.

Abstract: An analytical element for the detection of hydrogen peroxide comprising a peroxidase-functional material, a hydrogen donor and a coupler, wherein the peroxidase-functional material and hydrogen donor are arranged so as to be separate from each other, for example in separate layers, but are made interactive by the application of a fluid sample.

Abstract: A solid detecting reagent for gaseous hydrides and a gaseous hydride detecting method are disclosed, said reagent comprising a basic copper carbonate as a color changing component and undergoing color change upon contact with at least one gaseous hydride selected from the group consisting of arsine, phosphine, diborane, hydrogen selenide, germane, monosilane, disilane and dichlorosilane. The reagent is applicable to all of these gaseous hydrides and, upon contact therewith, rapidly changes from an initial blue color to a black color, said black color standing for a long period of time.

Abstract: A test pad having a water activated reagent and a water activated peroxygen compound which undergo a chromogen reaction in an aqueous solution including hemoglobin. The reagent is potassium guaiacolsulfonate, a guaiac substitute material. The peroxygen compound is a monopersulfonate compound comprised of two moles of potassium monopersulfonate, one mole of potassium hydrogen sulfate and one mole of potassium sulfate. The test pad features a test area containing the above materials in powdered form and may also include controls for checking the results of the test. A method for using the test pad is also disclosed.

Abstract: A test reagent system and method for detecting the presence of peroxidase-like activity is provided by the present invention. The reagent system comprises a free-flowing granular indicator material comprising a granular substrate such as sorbitol or mannitol having coated thereon gum guaiac and an aqueous organic reagent solution containing water, an organic solvent, an oxidizing agent being capable of oxidizing the indicator material in the presence of peroxidase-like activity, and a buffer.

Abstract: Devices and methods are provided for making a plurality of determinations of the local (site-specific) redox state of a liquid system, by employing a photoresponsive element, which can be independently irradiated at different sites to provide independently detectable signals.

Abstract: Ferric ion chelates are useful in analytical compositions, elements and methods for the determination of reductants, or other analytes which can produce a reductant. The ferric ion chelate is reduced to ferrous ion, which coordinates with a suitable ferrous ion coordinating ligand to form a colored complex. In particular, these compositions and elments are useful for detecting nicotinamide adenine dinucleotide, reduced form (NADH) or nicotinamide adenine dinucleotide phosphate, reduced form (NADPH), or an analyte (e.g. an enzyme) which produces NADH or NADPH in biological fluids.

Abstract: The invention comprises a method for determining the corrosion rate of metals in contact with a liquid system which is capable of causing corrosion of such metals which comprises adding to the liquid system an electrochemically active compound having a reduction potential more positive than the metal in contact with the liquid system and then monitoring the system thus treated with the electrochemically active compound to determine its rate of reduction which is proportional to the corrosion rate of the metal.

Abstract: The present invention relates to a novel method and apparatus which can provide continuous monitoring of the oxygen content of a gas over an indefinite period of time and at a minimal cost.In the novel apparatus of the present invention, a light source and a light sensitive detector are disposed within the atmosphere to be measured, and a polymeric film formed from a manganese tertiary phosphine polymer complex is deposited between the light source and the detector. As oxygen pressure increases or decreases a change in color intensity of the film takes place which controls passage of light from the light source to the detector. The detector in turn is suitably connected to an audio and/or visual warning device and/or a recorder which will provide the desired form of warning.

Abstract: An in-the-bowl occult blood test is provided with a flushable matrix having a separate testing site which will indicate the presence of residual oxidizing compounds in the toilet.

Abstract: Disclosed herein is a novel compound which is excellent in solubility to water around a neutral range, stable in an aqueous solution state for a long period of time, and high in coloring sensitivity with a stable coloring development, and is represented by the general formula (I): ##STR1## wherein R.sub.1, R.sub.2, R.sub.3 and R.sub.4, which may be the same as or different from one another, represent lower alkyl groups, and X.sub.1 and X.sub.2 both represent --O(CH.sub.2).sub.n SO.sub.3 M in which M is a hydrogen atom, an alkali metal ion or NH.sub.4.sup.+, and n is an integer of 2-4, or either of X.sub.1 and X.sub.2 represents --O(CH.sub.2).sub.n SO.sub.3 M in which M and n are the same meanings as given above and the other represents a hydrogen atom. This reagent is hardly susceptible of the influence of the serum components such as hemoglobin, bilirubin and so on due to its color having absorption on a longer wavelength side.

Abstract: The invention provides a reagent composition for detecting peroxidase-like activity in aqueous media, particularly for determining occult blood in fecal matter "in-the-bowl". The reagents comprise a dry mixture of a 3, 3', 5, 5' -tetramethylbenzidine and an alkali metal perborate, such as sodium perborate, and preferably also including a strong organic carboxylic acid such as citric acid and a sequesterant for trace metals such as ethylenediaminetetraacetic acid. The composition can be made increasingly more stable by coating the tetramethylbenzidine and an antioxidant with a water soluble polymer and or film coating the sodium perborate with a coating at least partially soluble in water. The reagents are deposited in porous or holed matrices including adsorbent paper, gelatin and molded polysaccharide film.

Abstract: A multilayer analytical element for analysis of analyte in a liquid sample comprising a liquid sample-spreading layer, a reagent layer containing a diazonium salt, and a liquid-impermeable light-transmissive support, being laminated in this order, in which said reagent layer contains a sulfonic acid group-containing polymer having at least 10 molar % of a repeating unit selected from those consisting of a sulfoalkyl group and sulfophenyl group. The analytical element can be an element comprising a porous reagent layer containing a diazonium salt and the liquid-impermeable light-transmissive support, being laminated in this order.

Abstract: The invention relates to the use of a compound of the chemical formula: ##STR1## in which: R.sub.1 and R.sub.2 are the same or different and represent hydrogen, halogen, and a lower alkyl or alkoxy group containing 1 to 4 carbon atoms, a (C.sub.1 -C.sub.4)-dialkylamino group, an acetylamino group, a nitro group or an aromatic group which may be substituted or anellated;n is an integer from 1 to 4, preferably 1 or 2;m is likewise an integer from 1 to 4, preferably 1 or 2; andR.sub.

Abstract: A quantitative, sensitive method for monitoring low concentrations of isothiazolones in aqueous systems is provided. The method involves the adsorption of the isothiazolones on a suitable adsorbent, the desorption of the adsorbed isothiazolones, the breaking of the isothiazolone ring and the formation of a blue complex by the reaction of the broken isothiazolone ring with ferric chloride and potassium ferricyanide. The concentration of the isothiazolones is then determined by conventional colorimetric techniques.

Abstract: A test kit for preparing a chemical test pad used in testing for the presence of occult blood in a specimen. The test kit is a foil package enclosing an absorbant pad bearing a peroxygen agent and a solution of guaiac in alcohol in a separate packet or compartment from the absorbant pad. The separate packet or compartment being rupturable by applying hand pressure to the outside of the foil package to mix the peroxygen agent powder on the test pad and the guaiac solution prior to removing the absorbant pad from the foil package. The method relates to performing a medical test by activating a test pad bearing one reagent by applying another reagent thereto while remaining wholly within a protective foil package. According to the method a test pad containing the peroxygen agent is wetted with a solution of guaiac in alcohol prior to removal from the protective foil package and exposure to a specimen of fecal material and water in a test for occult blood.

Abstract: The determination of fructosamine levels in at least part of a blood sample for use in detecting diabetes in patients or deciding treatment levels is effected by controlling the temperature and pH of the sample, adding a coloring agent such as a nitro-blue tetrazolium and after a first delay in time taking a first color measurment at a predetermined wavelength and after a second delay in time taking a second color measurement at the predetermined wavelength, then comparing any resultant change between the first and second color measurements with those of standard solutions, the selected timing delays, wavelength, coloring agent and pH conditions being such that any change of color in the coloring agent between the first and second color measurements is caused predominantly by the glucose in the sample that is reacted with an amine group of protein and has undergone a molecular rearrangement to form fructosamine and not materially by any non-specific reducing substance which may be present in the sample.

Abstract: A method and device for collecting and testing fecal occult blood which permits multiple analyses of a single fecal sample. The device is a combination of a sampler for collecting the fecal matter and a test slide. The fecal sampler comprises a pocket-like wipe pad for obtaining direct anal stool smears. An insert is disposed in the pocket of the wipe pad. The slide has a profiled opening similar to the design of the wipe pad. This opening acts as a receptacle for the pad when the fecal smear is transferred to the guaiac specimen receiving sheet of the slide. When the slide is closed the insert can be removed from the wipe pad. This design permits an analysis to be done on the specimen receiving sheet of the slide together with a second confirmatory test for human hemoglobin on portions of the insert. The fecal material on the insert is physically removed from the guaiac specimen receiving sheet.