New, simple maltogenic assay for mechanized determination of alpha-amylase activity in serum and urine. 1975

H F Proelss, and B W Wright

We report a new method for the mechanized determination of serum and urinary alpha-amylase by use of a continuous-flow system, based on the measurement of maltose formed by incubating the sample with amylodextrin at pH 7 and 40 degrees C. After dialysis, maltose is converted enzymatically to glucose, which is measured by Trinder's glucose oxidase-peroxidase method [J. Clin. Pathol. 22, 246 (1969)]. The reaction is linear for amylase activities up to 1400 Somogyi units/dl (2560 U/liter) and for maltose concentrations through 1500 mg/dl. No blank assay is required; consequently precision is improved and the automated system is simplified. Calibration with primary maltose standards increases accuracy and reliability. Common reducing substances in serum and urine do not interfere at their normal concentrations. There is a linear correlation between the results of this method and those of chromogenic and iodometric methods for normal and pathologic sera and urines. The chromogenic method yields significantly higher results and the iodometric method significantly lower results than this maltogenic method for elevated amylase activities. The normal range is 40-140 Somogyi units/dl (73-256 U/liter).

UI MeSH Term Description Entries
D007455 Iodine A nonmetallic element of the halogen group that is represented by the atomic symbol I, atomic number 53, and atomic weight of 126.90. It is a nutritionally essential element, especially important in thyroid hormone synthesis. In solution, it has anti-infective properties and is used topically. Iodine-127,Iodine 127
D008297 Male Males
D008320 Maltose A dextrodisaccharide from malt and starch. It is used as a sweetening agent and fermentable intermediate in brewing. (Grant & Hackh's Chemical Dictionary, 5th ed)
D010084 Oxidation-Reduction A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471). Redox,Oxidation Reduction
D002374 Catalase An oxidoreductase that catalyzes the conversion of HYDROGEN PEROXIDE to water and oxygen. It is present in many animal cells. A deficiency of this enzyme results in ACATALASIA. Catalase A,Catalase T,Manganese Catalase,Mn Catalase
D003124 Colorimetry Any technique by which an unknown color is evaluated in terms of standard colors. The technique may be visual, photoelectric, or indirect by means of spectrophotometry. It is used in chemistry and physics. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
D003912 Dextrins A group of low-molecular-weight carbohydrates produced by the hydrolysis of STARCH or GLYCOGEN. They are mixtures of polymers of D-glucose units linked by alpha-(1->4) or alpha-(1->6) glycosidic bonds. Dextrin
D005069 Evaluation Studies as Topic Works about studies that determine the effectiveness or value of processes, personnel, and equipment, or the material on conducting such studies. Critique,Evaluation Indexes,Evaluation Methodology,Evaluation Report,Evaluation Research,Methodology, Evaluation,Pre-Post Tests,Qualitative Evaluation,Quantitative Evaluation,Theoretical Effectiveness,Use-Effectiveness,Critiques,Effectiveness, Theoretical,Evaluation Methodologies,Evaluation Reports,Evaluation, Qualitative,Evaluation, Quantitative,Evaluations, Qualitative,Evaluations, Quantitative,Indexes, Evaluation,Methodologies, Evaluation,Pre Post Tests,Pre-Post Test,Qualitative Evaluations,Quantitative Evaluations,Report, Evaluation,Reports, Evaluation,Research, Evaluation,Test, Pre-Post,Tests, Pre-Post,Use Effectiveness
D005260 Female Females
D005949 Glucose Oxidase An enzyme of the oxidoreductase class that catalyzes the conversion of beta-D-glucose and oxygen to D-glucono-1,5-lactone and peroxide. It is a flavoprotein, highly specific for beta-D-glucose. The enzyme is produced by Penicillium notatum and other fungi and has antibacterial activity in the presence of glucose and oxygen. It is used to estimate glucose concentration in blood or urine samples through the formation of colored dyes by the hydrogen peroxide produced in the reaction. (From Enzyme Nomenclature, 1992) EC 1.1.3.4. Microcid,Oxidase, Glucose

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