A tableted enzymic reagent for salicylate, for use in a discrete multiwavelength analytical system (Paramax).

1984 ◽  
Vol 30 (8) ◽  
pp. 1369-1371 ◽  
Author(s):  
R W Longenecker ◽  
J E Trafton ◽  
R B Edwards
Keyword(s):  
Carbon Dioxide ◽  
High Sensitivity ◽  
Reaction Volume ◽  
Final Reaction ◽  
Salicylate Concentration ◽  
Absorbance Change ◽  
Sample Error ◽  
Analytical System ◽  
Final Reaction Volume

Abstract A fully enzymic reagent for determination of salicylate in serum has been developed for use in the Paramax analytical system. The assay, run as an equilibrium determination, is based on the reaction of salicylate with NADPH and oxygen in the presence of salicylate hydroxylase (EC 1.14.13.1) to form catechol, NADP+, carbon dioxide, and water. The reaction is complete within 7 min, after which time the resulting absorbance change at 340/405 nm is measured. The sample:reagent ratio is 1:60 (5 microL of sample in a 300 microL final reaction volume). A single 30-mg tablet contains all of the reactants with tableting excipients. The use of NADPH eliminates interferences from reactions involving NADH. The large sample:reagent ratio, high sensitivity, and choice of bichromatic wavelengths minimize sample error. Results are linearly related to salicylate concentration to 1500 mg/L. Precision (CV) is 1.7% at 540 mg/L and 2.4% at 280 mg/L.

scholarly journals An alternative method for Staphylococcus aureus DNA isolation

2008 ◽  
Vol 60 (2) ◽  
pp. 299-306 ◽  
Author(s):  
L. Chapaval ◽  
D.H. Moon ◽  
J.E. Gomes ◽  
F.R. Duarte ◽  
S.M. Tsai
Keyword(s):  
Staphylococcus Aureus ◽  
Genomic Dna ◽  
Dna Isolation ◽  
Environmental Isolates ◽  
Reaction Volume ◽  
High Quality ◽  
Rapid Procedure ◽  
Final Reaction ◽  
Staphylococcal Enterotoxins ◽  
Final Reaction Volume

This study describes a rapid procedure for the isolation of genomic DNA from Staphylococcus aureus that yielded a good amount of high quality DNA for the amplification of staphylococcal enterotoxins genes (A, B, C, D, and E) and the TSST-1 gene as well as enzymatic restriction (HaeIII) from environmental isolates. With this method, it was possible to detect these genes in a sample containing as little as 10(5) cells with positive PCR reactions obtained from approximately 10pg of DNA in a final reaction volume of 25µl.

Measurement of Erythrocyte Glucose-6-Phosphate Dehydrogenase Activity with a Centrifugal Analyzer

1975 ◽  
Vol 21 (1) ◽  
pp. 134-138 ◽  
Author(s):  
Edward W Catalano ◽  
George F Johnson ◽  
Harvey M Solomon
Keyword(s):  
Dehydrogenase Activity ◽  
Regression Line ◽  
Reaction Volume ◽  
Phosphogluconate Dehydrogenase ◽  
Standard Assay ◽  
Variable Contribution ◽  
Glucose 6 Phosphate Dehydrogenase ◽  
Improved Methods ◽  
Final Reaction Volume

Abstract We describe two improved methods for determination of erythrocyte glucose-6-phosphate dehydrogenase activity. One method is an"enzyme-linked" procedure in which an excess of 6-phosphogluconate dehydrogenase is used to produce two moles of NADPH for each mole of glucose-6-phosphate oxidized. In the other method 2,3-diphosphoglycerate is used to inhibit the variable contribution of endogenous 6-phosphogluconate dehydrogenase to glucose-6-phosphate dehydrogenase activity in erythrocyte lysates. These assays require 100 µl of blood and are performed on a centrifugal analyzer in a final reaction volume of 410 µl at 37 °C. NADPH formation is monitored at 340 nm. Hemoglobin is measured as oxyhemoglobin in the same reaction mixture used to determine enzyme activity by changing the wavelength to 550 nm. Results are expressed as international units of glucose-6-phosphate dehydrogenase activity per gram of hemoglobin. The coefficient of correlation between "enzyme-linked" assay and "standard" assay was .992, the slope of the regression line was 1.07, and the intercept was at -0.76. When results of the "enzyme-linked" assay were compared to those of the "nonlinked" assay with added 2,3-diphosphoglycerate, the slope of the regression line was .994, the intercept 0.109, and the correlation coefficient .994.

Atomic absorption determination of Hg (II), Cd (II), and As (III) in natural and waste water after preliminary group preconcentration

2019 ◽  
Vol 85 (2) ◽  
pp. 12-16
Author(s):  
I. V. Saunina ◽  
E. N. Gribanov ◽  
E. R. Oskotskaya
Keyword(s):  
Waste Water ◽  
Atomic Absorption ◽  
High Sensitivity ◽  
Distribution Coefficients ◽  
Neutral Medium ◽  
Atomic Absorption Determination ◽  
Absorption Determination ◽  
Relative Standard ◽  
Preliminary Group

The sorption of Hg (II), Cd (II), and As (III) by natural aluminosilicate is studied. It is shown that the mineral absorbs those toxicants in a rather wide pH range, quantitative extraction of analytes being achieved in a neutral or close to neutral medium (pH values range within 7.0 - 8.0; 6.3 - 7.5; 7.4 - 8.5 for Hg (II), As (III), and Cd (II), respectively). The effect of the time of phase contact on the degree of extraction of elements is shown. The sorption capacity of the mineral in optimal conditions of the medium acidity (0.06 mmol/g for mercury, 0.31 mmol/g for cadmium, and 0.52 mmol/g for arsenic) is determined. The distribution coefficients attain values of aboutnX 103-nX 104. A new combined method for determination of Hg (II), Cd (II), and As (III) in natural and waste water is developed and tested. The method consists in a preliminary group sorption concentration of the analytes by aluminosilicate, desorption of the analytes from the surface of the mineral and their subsequent atomic absorption determination. The correctness of the method is verified in analysis of spiked samples. The method is easy to use and exhibits high sensitivity, reproducibility and accuracy of analyte determination. The relative standard deviation does not exceed 0.13. Economic availability and possibility of using domestic sorption materials are the important advantages of the proposed procedure which can be used in the practice of laboratories monitoring the quality and safety of environmental objects.

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