Biomedical subjects

M V Honchar

Publications and source records attributed to M V Honchar.

4 recordsLinked to original sources

PubMedDate not supplied

[A sensitive method for quantitative analysis of hydrogen peroxide and oxidase substrates in biological samples].

The sensitive method for peroxidative assays of hydrogen peroxide (up to 5 nmole in 1 ml) and oxidases' substrates (glucose, ethanol) has been developed by use of a non-cancerogenic chromogen--3,3', 5,5'-tetramethylbenzidine (TMB), horseradish peroxidase and corresponding oxidases. The proposed modification of the known method consists in using decreased concentration of TMB (0.05-0.1 mM) and stopping the reaction by adding of acid to pH 1.4-2.1. This approach allowed to enhance the sensitivity of assays of corresponding analytes (7-10 times) and decrease the costs of analysis.

Benzidines↗

PubMedDate not supplied

[Metabolic engineering in design of cellular elements of biosensors].

An extended definition of the term "metabolic engineering" is given and main spheres of its using in fundamental studies and modern biotechnology are discussed in this article. Emphasis is made on specific using the approaches of metabolic engineering in construction of the cell elements of sensors based on the use of mutant and chemically modified cells of methylotrophic yeasts. This investigation is designed in the laboratory of Biochemical Genetics of the Division of Cell Regulatory Systems, A. V. Palladin Institute of Biochemistry. Genetic and chemical modifications have allowed to provide some directed changes in cell sensoring output toward methanol, ethanol and formaldehyde that result in enhanced selectivity and shortened time-output of the corresponding potentiometric and amperometric sensors.

Biomedical Engineering↗

PubMedDate not supplied

[A new oxidase method for analyzing L-lactate].

A new oxidase-coupled colorimetric method for analysis of L-lactate in biological fluids has been developed without use of peroxidase. The method is based on lactate oxidase-catalysed transformation of lactate to pyruvate which is determined photometrically in the next dye-producing reaction of 3-methyl-2-benzothiazolinone hydrazone (MBTH) in the presence of ferric ions. Sensitivity of the method is estimated as 0.1 micromole of analyte in 4-ml of reaction mixture. Linearity is observed in the range 0.1-1.0 micromole of L-lactate in sample (r = 0.99943; p < 0.0001). The developed method has been adapted for assay of L-lactic acid in kefirs and yogurts.

Catalysis↗

PubMedDate not supplied

[Quantitative photometric analysis of ethanol using purified alcohol oxidase and mutant cells of methylotrophic yeast].

The photometric method is suggested for ethanol analysis by means of purified alcohol oxidase isolated from a wild strain of methylotrophic yeast Hansenula polymorpha. Three different chromogenic systems for peroxidative oxidation together with alcohol oxidase reaction have been used. For the first time the intact cells of the catalase-negative mutant as a source of alcohol oxidase are employed in the photometric alcohol assay. The prospects for application of the latter method for practical purposes are discussed.

Alcohol Oxidoreductases↗