Abstract: A process and a reagent for the determination of .alpha.-amylase involve enzymatic splitting of an .alpha.-amylase substrate in the presence of .alpha.-glucosidase and .beta.-glucosidase and measurement of a fission product. As substrate, there is used a 4-nitrophenyl-.beta.,D-maltoheptaoside electronegatively substituted in the phenyl nucleus.

Abstract: A process and reagent are described for the determination of .alpha.-amylase by enzymatic splitting of an .alpha.-amylase substrate in the presence of .alpha.-glucosidase and .beta.-glucosidase and measurement of a fission product. The substrate utilized is a 4-nitrophenyl-.beta.,D-maltoheptaoside substituted in the phenyl ring by an electron withdrawing group, preferably a 2-chloro group.

Abstract: A test system having an extended range of measurement and an appropriate procedure for the determination of NAD(P)H or of substrates or enzymes which react to form or consume NAD(P)H in fluids is provided. The test system contains, at one and the same time, several substances acting independently of one another as electron acceptors with respect to NAD(P)H and having different electrochemical potentials. Addition of the test system to the sample solution gives rise to different end products which can be analytically differentiated and which are evaluated visually or by other techniques of measurement.

Abstract: A test system having an extended range of measurement and a corresponding procedure for the determination of substances in liquids contains several enzymes or enzyme systems together which, independently of one another, react directly or indirectly with the substance to be determined. On adding the test system to the sample solution, various final products are produced which can be distinguished analytically and evaluated by measurement techniques or visually. For example, glucose can be determined over a wide range of concentrations using a combination of an NAD-dependent dehydrogenase and a non-NAD-dependent dehydrogenase.

Abstract: Alkaline phosphatase is stabilized in buffer solutions. This is accomplished by adding a water soluble complex of zinc ions and a chelating agent to the buffer.

Abstract: A hemolysing solution for use in the determination of glucose in a whole blood sample which comprises (a) a buffer providing a pH of about 6-8, (b) sodium chloride, (c) a surface active agent and, (d) a chelating agent which in the presence of component (c) serves as a stabilizer against glycolysis in the hemolysate obtained by contacting the blood sample with said hemolysing solution.

Abstract: A stable, aqueous, substantially alcohol-free lipid standard solution, comprising water, at least one lipid, and an effective lipid-solubilizing amount of both a non-ionic detergent and an ionic detergent. A simple, convenient method for making such a solution is provided.

Abstract: In a method for detection and/or assay of hydroperoxides (or, indirectly, of substances, such as cholesterol or glucose, which react to liberate hydroperoxides) using an assay reagent comprising a water-soluble iodide, a redox catalyst and a stabilizer, an improvement is provided wherein when the determination is made in the presence of protein, the redox catalyst concentration in the reagent is 5-500 .mu.M and the stabilizer concentration in the reagent is 5-100 mg/l. A corresponding improvement in the assay reagent is also provided.

Abstract: Process for the isolation of component materials of aqueous solutions by adsorption of the aqueous solutions on concentration agents based on silica gel and/or kieselguhr and subsequent extraction of the component materials with lipophilic solvents, which employs as concentration agents flowable silica gels and/or kieselguhrs with an average particle size of 0.05 to 1.0 mm., an average pore volume of 0.2 to 3 ml./g., and a specific surface of 0.2 to 50 m.sup.2 /g.

Abstract: Glucose is rapidly ad quantitatively determined with an analytical agent containing glucose dehydrogenase having an activity of at least 2 .mu./mg and NADH.sub.2 oxidase activity less than 0.1%, a pyridine coenzyme, a buffer and mutarotase to increase spontaneous mutarotation of alpha-glucose to beta-glucose. There may be optionally present inhibitors for reduced pyridine coenzyme oxidases and a thermal stabilizing amount of alkali metal chloride.