Abstract: A stable single reagent for the determination of carbon dioxide in serum is provided as an aqueous solution of diagnostically amounts and NADH and/or NADPH, and a stabilizing system therefore reactively stabilized PEPC and a substrate for reacting with bicarbonate ion under alkaline conditions in the presence of PEPC.

Abstract: A method for stabilizing analytes with antibodies and antibody fragments comprises dissolving the analyte in a liquid to form a solution, adding analyte-specific antibodies, fragments of such antibodies, or both to the solution, heating the solution, and then cooling and filtering the solution. The filtered solution may be diluted in a suitable matrix.

Abstract: In a single liquid alpha-amylase reagent composition comprising an aqueous solution of at least one substrate which is hydrolyzed when mixed with a sample of body fluid containing alpha-amylase to yield a detectable label, alpha-glucosidase from Bacillus stearothermophilus is used to cooperate with the alpha-amylase in the formation of the detectable label and the composition being stable against degradation for a least 6 months at 2.degree. to 10.degree. C.

Abstract: A single system reagent for the determination of lipase, formulated as an emulsion comprising a lipase-active fatty acid source; a first lipase activator comprising colipase; a second lipase activator; a lipoprotein lipase inhibitor; an emulsion stabilizer comprising Triton X100; a buffer; and an antiprecipitant.

Abstract: A single system reagent for the determination of lipase, formulated as an emulsion comprising a lipase-active fatty acid source; a first lipase activator comprising colipase; a second lipase activator; a lipoprotein lipase inhibitor; a first emulsion stabilizer comprising Triton X100; a second emulsion stabilizer; a buffer; and an anti-precipitant.

Abstract: A stable triglyceride assay solution for use with a chromogen system is comprised of a solution buffered with a Zwitterionic buffering agent and/or TRIS and stabilized with sortibol, gelatin, and ammonium sulfate. Solution pH is in the range of from 6.8 to 8.0. The functional enzymes are lipase, glyercol kinase, and glycerol phosphate oxidase. The preferred chromogen system is based on the inclusion of 4-aminoantipyrine for use in combination with oxidase to yield a detectable chromogen compound.

Abstract: There is provided a stable cholesterol assay composition which comprises an aqueous solution of at least one bile acid or salt thereof being present in an amount of up to about 5 mM; a nonionic surfactant present in an amount of from about 0.15 to about 1.5 percent volume by volume; a buffer in a concentration of from 0 to about 65 mM; and cholesterol oxidase in a concentration of at least about 0.1 kIU/l. Solution pH is from about 5.5 to about 8.5. Addition of cholesterol esterase, phenol, peroxidase and 4-aminoantipyrine provides a total cholesterol chromogen system.

Abstract: A method is disclosed for preparing a soluble stable enzyme. The method comprises the steps of reacting in a liquid media an enzyme with a polymer having pendant groups capable of covalently bonding with pendant groups on the enzyme. The enzyme and polymer are mixed with at least one composition which affects the activity of the enzyme. Such a composition can be selected from the enzyme substrate, product of the enzyme substrate reaction, an activator for the enzyme and/or inhibitor for the enzyme. In addition, a composition can be added which can also competitively react with the available pendant groups of the polymer.