Results 261 to 270 of about 282,094 (307)
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A quantitative colorimetric assay for semialdehydes
Analytical Biochemistry, 1990We have studied the ability of the enzyme pyrroline-5-carboxylate dehydrogenase to oxidize aldehydes which are structurally similar to pyrroline-5-carboxylate, the enamine of gamma-glutamyl semialdehyde. These studies required the organic synthesis of semialdehydes not commercially available.
W C, Small, M E, Jones
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A colorimetric formaldehyde assay
Applied Biochemistry and Biotechnology, 1997A room-temperature assay of formaldehyde is described. The assay uses few reagents and is colorimetric, read at a wavelength of 649 nm. Tryptophan and tryptamine were noted as interfering with the assay, probably by binding with the formaldehyde. High levels of sugar show smaller effects on final absorbance. Glyceraldehyde also reacts in the assay, but
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Colorimetric Assay for Acetaminophen in Serum
Therapeutic Drug Monitoring, 1984A colorimetric method for determination of acetaminophen in serum, based on its reaction with 2-nitroso-1-naphthol-4-sulfonic acid, is described. The method is sensitive, rapid, and free from the interferences of serum matrix and most common drugs. The method can be performed manually or can be semiautomated. The results from this method correlate well
Z K, Shihabi, R M, David
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An ultrasensitive colorimetric assay for manganese
Analytical Biochemistry, 1988An ultrasensitive colorimetric assay for manganese is described. It is based upon the catalysis, by Mn(II), of the photochemical oxidation of o-dianisidine, sensitized by riboflavin. Catalase increases the Mn(II)-catalyzed rate of photosensitized oxidation of dianisidine to the bisazobiphenyl, while superoxide dismutase inhibits the rate. The mechanism
W F, Beyer, I, Fridovich
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Arylsulfatases: Colorimetric and fluorometric assays
1987Publisher Summary This chapter discusses the colorimetric and fluorometric assays of arylsulfatases. The assay of arylsulfatases is simple in principle, and any of the reaction products may be determined. The general method is simple and requires only that the reaction mixture, after incubation with the enzyme, be made alkaline so that the liberated ...
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A colorimetric assay for immobilized chloroperoxidase
Canadian Journal of Microbiology, 1990A rapid and sensitive colorimetric assay was developed for the estimation of chloroperoxidase activity. N,N,N′,N′-Tetramethyl-p-phenylenediamine was chosen from four potential chromogenic substrates because the blue product resulting from chloroperoxidase conversion gave the highest molar absorption.
T A, Kadima, M A, Pickard
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1990
Abstract : Using rat serum as a source of esterase activity, we describe a quick and efficient method of taking advantage of the water solubility of the paranitrophenoxide anion. Esterase activity is terminated by adding chloroform and releasing paranitrophenol converted to the 400 nanometers absorbing paranitrophenoxide anion by adding 0.2 molar ...
James P. Chambers, James J. Valdes
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Abstract : Using rat serum as a source of esterase activity, we describe a quick and efficient method of taking advantage of the water solubility of the paranitrophenoxide anion. Esterase activity is terminated by adding chloroform and releasing paranitrophenol converted to the 400 nanometers absorbing paranitrophenoxide anion by adding 0.2 molar ...
James P. Chambers, James J. Valdes
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A rapid colorimetric assay for DNA
Analytical Biochemistry, 1977Abstract A rapid precise colorimetric method for the determination of DNA in the range of 25–1000 μg is reported. The method involves reacting DNA with diaminobenzoic acid · 2HCl (DABA) for 30 min at 60°C, followed by a determination of the optical density of the product at 420 nm. Perchloric acid extracts of DNA may be used in the assay.
F, Setaro, C D, Morley
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Applied Biochemistry and Biotechnology, 1995
A new spectrophotometric method for measuring fructose is presented. The method uses Tryptamine in HCl acid, is carried out at 60°C, and is complete within 60 min. The assay is read at 518 nm and shows very low interference from other sugars. The method can be used for fructose, fructosans, and inulin.
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A new spectrophotometric method for measuring fructose is presented. The method uses Tryptamine in HCl acid, is carried out at 60°C, and is complete within 60 min. The assay is read at 518 nm and shows very low interference from other sugars. The method can be used for fructose, fructosans, and inulin.
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A quantitative colorimetric assay for squalene
Analytical Biochemistry, 1962Abstract A rapid and sensitive quantitative colorimetric test for squalene has been devised. The color reaction involves the use of sulfuric acid and formaldehyde. The test will give a positive reaction with other compounds which contain double bonds and must consequently be used in conjunction with other methods which yield purified squalene.
G H, ROTHBLAT +2 more
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