Fluorescence assay of tyrosine in blood plasma

Autor: V. B. Gavrilov, E. P. Shostak, S. V. Konev, A. V. Lychkovskii
Rok vydání: 1998
Předmět:
Zdroj: Journal of Applied Spectroscopy. 65:379-384
ISSN: 1573-8647
0021-9037
Popis: A more simple and sensitive assay for the quantitative determination of tyrosine in blood plasma is developed on the basis of a modification of the method of S. Udenfriend (1962). A volume of 0.2 ml of plasma is used in the analysis; after its deproteinization with trichloroacetic acid, it is reacted with sodium nitride, nitrous acid, and 1-nitroso-2-naphthol at 65°C, and the content of the reaction product is measured by the fluorescence at λex/λem=460/570 nm. The consumption of plasma and reagents is reduced by a factor of 5–10 compared to the original method; in addition, the stage of extraction with an organic solvent is excluded. The linear dependence of the fluorescence signal on the tyrosine concentration within the range of 2–60 μg/ml, high specificity, accuracy, and reproducibility of the assay are shown. The importance of tyrosine determination in monitoring of glucocorticoid therapy and protein catabolism is discussed.
Databáze: OpenAIRE
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