Automated Method for Determining Amylase Activity in Serum and Urine

1973 ◽  
Vol 19 (10) ◽  
pp. 1187-1192 ◽  
Author(s):  
A Mazzuchin ◽  
C Weggel ◽  
C J Porter
Keyword(s):  
Amylase Activity ◽  
Water Soluble ◽  
Standard Curve ◽  
The Past ◽  
Automated Method ◽  
Wide Range ◽  
On Line ◽  
Starch Substrate ◽  
Suspended Substrate

Abstract We describe an automated procedure for determination of α-amylase activity in serum or urine by use of a water-insoluble chromogenic starch substrate (commercially available). "AutoAnalyzer" (Technicon Corp.) equipment is used in which the sample and suspended substrate are introduced simultaneously into the flow system. After incubation at 37 °C the water-soluble blue-starch breakdown products are filtered on-line across a cellulose nitrate membrane. Absorbance is measured at 630 nm, and the α-amylase activity read from a standard curve. The automated procedure has been in use for the past year and has been found to be an operationally simple, reproducible, and reliable method, which can be applied over a wide range of enzyme activity. Results of comparative studies with other α-amylase methods are also described.

scholarly journals Alternative method for quantification of alfa-amylase activity

2010 ◽  
Vol 70 (2) ◽  
pp. 405-407 ◽  
Author(s):  
DF. Farias ◽  
AFU. Carvalho ◽  
CC. Oliveira ◽  
NM. Sousa ◽  
LCB. Rocha-Bezerrra ◽  
...  
Keyword(s):  
Enzyme Activities ◽  
Amylase Activity ◽  
Scientific Investigation ◽  
Diffusion Method ◽  
Teaching Laboratory ◽  
Standard Curve ◽  
Wide Range ◽  
Macro Scale ◽  
Agar Diffusion Method

A modification of the sensitive agar diffusion method was developed for macro-scale determination of alfa-amylase. The proposed modifications lower costs with the utilisation of starch as substrate and agar as supporting medium. Thus, a standard curve was built using alfa-amylase solution from Aspergillus oryzae, with concentrations ranging from 2.4 to 7,500 U.mL-1. Clear radial diffusion zones were measured after 4 hours of incubation at 20 °C. A linear relationship between the logarithm of enzyme activities and the area of clear zones was obtained. The method was validated by testing α-amylase from barley at the concentrations of 2.4; 60; 300 and 1,500 U.mL-1. The proposed method turned out to be simpler, faster, less expensive and able to determine on a macro-scale α-amylase over a wide range (2.4 to 7,500 U.mL-1) in scientific investigation as well as in teaching laboratory activities.

An Automated Detection System for Most L-α-Amino Acids

1969 ◽  
Vol 15 (2) ◽  
pp. 154-161 ◽  
Author(s):  
K Van Dyke ◽  
C Szustkiewicz
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Detection System ◽  
Automated System ◽  
Acid Oxidase ◽  
Enzymatic Reactions ◽  
Amino Acid Oxidase ◽  
Automated Method ◽  
Wide Range

Abstract An automated system for the determination of the L-α form of the majority of amino acids is presented. The method is based upon oxidative deamination of the amino acid coupled with oxidation of o-dianisidine by hydrogen peroxide. This procedure can be used comparatively for the determination of a mixture of L-α-amino acids or for the majority of separated L-α-amino acids (especially in conjunction with column separations from urine and blood which give falsely positive identification with ninhydrin detection). The stereospecific nature of the L-α-amino acid oxidase enables the investigator to quantitate the amount of L-α-amino acid in the presence of the D-α form. From an academic viewpoint, the extreme sensitivity and wide range of the detection system make it advantageous for the study of the enzyme itself. This automated method also may be employed to follow enzymatic reactions—e.g., those catalyzed by peptidases or racemases. The methodology is extremely convenient with good reagent stability and is much more sensitive than manometric technics.

Passing the Baton:

2003 ◽  
Vol 3 (3-4) ◽  
pp. 191-195
Author(s):  
Jerry Dupont
Keyword(s):  
Digital Library ◽  
The Past ◽  
Wide Range ◽  
The Us ◽  
On Line ◽  
The Law ◽  
The Uk ◽  
Law Library

I work for the Law Library Microform Consortium (LLMC), a cooperative with some 900 participating members. Most are in the US, with a fair number in Canada and some in Australia, the UK and sixteen other countries. For over a quarter of a century LLMC has provided its member libraries with a wide range of legal titles, including much Commonwealth material, on microfiche. We grew hoary in that task, but have been rejuvenated in a new role. We've just launched an on-line digital library, LLMC-Digital, which will provide vastly enhanced access to our materials. The foundation for this endeavour is our backfile of 92,000 volumes (some 49-million page images) filmed during the past 27 years. To that base will be added every new title acquired in LLMC's future filming or scanning.

An Automated Method for the Continuous Determination of Total Sodium in Fuel Oil

1978 ◽  
Author(s):  
L. P. Giering
Keyword(s):  
Gas Turbines ◽  
Fuel Oil ◽  
Reliable Measurement ◽  
Continuous Analysis ◽  
Automated Method ◽  
Fuel Oils ◽  
On Line ◽  
Total Sodium ◽  
Continuous Determination

Fuel oils are frequently contaminated with sodium salts. Users of gas turbines are concerned with the level of sodium in fuel because of the deleterious effects to the turbine. Until recently, on-line continuous methods of analysis did not reliably measure the total sodium in a given fuel. A method is described for the continuous analysis of total sodium present in fuel oils regardless of its chemical form. A small amount of surfactant, “Liquid G” is added to the fuel, and the total sodium in the resulltant solution is determined by flame photometry. The method described provides for the continuous and reliable measurement of sodium in fuel.

scholarly journals Antioxidant Properties of Fullerene Derivatives Depend on Their Chemical Structure: A Study of Two Fullerene Derivatives on HELFs

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Vasilina Sergeeva ◽  
Olga Kraevaya ◽  
Elizaveta Ershova ◽  
Larisa Kameneva ◽  
Elena Malinovskaya ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Chemical Structure ◽  
Antioxidant Properties ◽  
Water Soluble ◽  
Lung Fibroblasts ◽  
Human Embryonic Lung ◽  
Fullerene Derivatives ◽  
The Past ◽  
Wide Range ◽  
Short Times

Oxidative stress is a major issue in a wide number of pathologies (neurodegenerative, cardiovascular, immune diseases, and cancer). Because of this, the search for new antioxidants is an important issue. One of the potential antioxidants that has been enthusiastically discussed in the past twenty years is fullerene and its derivatives. Although in aqueous solutions fullerene derivatives have shown to be antioxidants, their properties in this regard within the cells are controversially discussed. We have studied two different water-soluble fullerene C60 and C70 derivatives on human embryonic lung fibroblasts at a wide range of concentrations. Both of them cause a decrease in cellular ROS at short times of incubation (1 hour). Their prolonged action, however, is fundamentally different: derivative GI-761 causes secondary oxidative stress whereas derivative VI-419-P3K keeps ROS levels under control values. To gain a better understanding of this effect, we assessed factors that could play a role in the response of cells to fullerene derivatives. Increased ROS production occurred due to NOX4 upregulation by GI-761. Derivative VI-419-P3K activated the transcription of antioxidant master regulator NRF2 and caused its translocation to the nucleus. This data suggests that the antioxidant effect of fullerene derivatives depends on their chemical structure.

Determination of alpha-amylase activity: methods comparison and commutability study of several control materials

1995 ◽  
Vol 41 (3) ◽  
pp. 435-438 ◽  
Author(s):  
G Gubern ◽  
F Canalias ◽  
F J Gella
Keyword(s):  
Human Serum ◽  
Amylase Activity ◽  
Alpha Amylase ◽  
Human Origin ◽  
Serum Samples ◽  
Chromophore Group ◽  
Laboratory Control ◽  
Wide Range ◽  
Human Sera

Abstract Six different methods for alpha-amylase determination were compared by assaying human serum samples covering a wide range of alpha-amylase values. All the methods studied use as substrate a maltooligosaccharide with a chromophore group at the reducing end; some are chemically blocked at the nonreducing end. Intermethod comparison by regression and correspondence analyses showed significant differences for two methods. The commutability of 12 commercial control materials containing alpha-amylase was also assessed by the different methods in comparison with human serum specimens containing the pancreatic and salivary isoenzymes. We also studied the behavior of pancreatic and salivary materials prepared in our laboratory. Control materials with alpha-amylase of non-human origin were not commutable with the enzyme in human sera and should not be used for intermethod calibration.

scholarly journals A Simple Automated Method for the Determination of Nitrate and Nitrite in Infant Formula and Milk Powder Using Sequential Injection Analysis

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Mariela Pistón ◽  
Alicia Mollo ◽  
Moisés Knochen
Keyword(s):  
Milk Powder ◽  
Sequential Injection Analysis ◽  
Sequential Injection ◽  
Liquid Form ◽  
Automated Method ◽  
Nitrate Determination ◽  
On Line ◽  
Nitrate And Nitrite ◽  
User Friendly

A fast and efficient automated method using a sequential injection analysis (SIA) system, based on the Griess, reaction was developed for the determination of nitrate and nitrite in infant formulas and milk powder. The system enables to mix a measured amount of sample (previously constituted in the liquid form and deproteinized) with the chromogenic reagent to produce a colored substance whose absorbance was recorded. For nitrate determination, an on-line prereduction step was added by passing the sample through a Cd minicolumn. The system was controlled from a PC by means of a user-friendly program. Figures of merit include linearity (r2> 0.999 for both analytes), limits of detection (0.32 mg kg-1NO3-N, and 0.05 mg kg-1NO2-N), and precision (sr%) 0.8–3.0. Results were statistically in good agreement with those obtained with the reference ISO-IDF method. The sampling frequency was 30 hour-1(nitrate) and 80 hour-1(nitrite) when performed separately.

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