Abstract: The operative site of an assay device is dosed with a controlled volume of a liquid specimen by a holding device which holds the controlled volume of specimen in contact with the operative site, although the holding device remains out of contact with the operative site. A sink device is in contact with the margin of the holding device and moves excess specimen away from the holding device. In one embodiment the device makes possible a non-wipe teststrip architecture. The device can be used in the detection of analytes including glucose or cholesterol in blood or urine and can be interrogated visually, optically or electrically, depending on the reagent used at the operative site.

Abstract: Non-aqueous, polymeric reagent film compositions for use with analytical test devices of the dry chemistry type are described. The film compositions are prepared from an organic solution of a copolymer formed by interaction of at least two monomers wherein(a) the first monomer is a hydroxylated acrylate of the general formula ##STR1## where R1 is hydrogen or, more preferably, methyl, and R2 is a hydroxyalkyl group having from 1 to 5 carbon atoms, and(b) the second monomer is a neutral acrylate of the general formula ##STR2## where R1 is hydrogen or, more preferably, methyl, and R3 is a substituted or unsubstituted alkyl group having from 1 to 8 carbon atoms.Preferably, a third monomer is also included which is an amine-containing acrylate of the general formula ##STR3## where R1 is hydrogen or, more preferably, methyl, and R4 is a substituted or unsubstituted aminoalkyl or glycidyl group having from 1 to 5 carbon atoms or a surfactant polyethylene glycol group having from 10 to 30 carbon atoms.

Abstract: Novel reagent compositions and an assay method for the measurement of total and direct bilirubin are disclosed. The reagent compositions comprise an aqueous solution of at least one betaine selected from the group of alkyl betaine, betaine and betaine hydrate, a sulfanilamide diazonium salt, iodide ions and sulfamic acid. In the measurement of total bilirubin, alkyl betaine serves as an accelerator/solubilizer for the reaction of unconjugated bilirubin, and the alkyl betaine, betaine or betaine hydrate, together with iodide ions, minimizes or substantially eliminates interference from hemoglobin and lipemia.

Abstract: An improved colorimetric assay method and reagent composition for the quantitative determination of creatinine in biological fluid specimens in the presence of protein, in which the specimen is reacted directly with an alkaline picrate reagent composition which contains an iron chelator, preferably ethylenediaminetetraacetic acid, thereby significantly suppressing interference from bilirubin and improving reagent stability.

Abstract: An improved diagnostic assay and stabilized reagent composition for the determination of .gamma.-glutamyltransferase activity in biological specimens using a buffered solution of .gamma.-glutamyl-p-nitroanilide and glycylglycine, wherein .beta.-cyclodextrin and preferably also dimethylsulfoxide have been added thereto.

Abstract: A precision metering device for very small quantities of fluids, in which a controlled deflection of one or more selected portions of a Bourdon tube are used to give precise metering of fluids in amounts of only a few microliters or less, and in which a single one of the precision metering devices may be used to provide selected variations of the small amounts of dispensed fluid and with different fluids, usually without extra purging procedures.

Abstract: An improved assay method and reagent composition for the determination of magnesium in a fluid sample by reaction with an alkaline buffered solution of calmagite, in which caffeine and preferably also thiourea have been included, thereby achieving parity between protein-free and protein-containing samples while eliminating the need for cyanide.

Abstract: A colorimetric assay method and reagent composition for the direct, quantitative determination of chloride in fluids which may be performed directly on non-deproteinized samples and which utilizes a reagent comprised of 2,4,6-tripyridyl-s-triazine, mercuric ions, ferrous ions, and a sulfate salt in a sulfate or sulfonate buffer at a selected pH in the range of about 1.5 to 3.0.