A Fluorometric Method for Plasma Cortisol and Transcortin

Modified fluorometric method for determining plasma catecholamines.

Plasma catecholamines were fluorometrically determined by a modification of the standard alumina-trihydroxyindole method in which radioactive tracer catecholamines are used to follow the chromatographic behavior of the endogenous catecholamines on alumina. This modification permits appropriate fluorometry of that portion of the eluate with the highest concentration of catecholamines, because in...

Nonspecific interferences in the fluorometric determination of plasma cortisol.

The popular Mattingly [J. Gun. Pathol. 15, 374 (1962)] fluorometric assay for plasma cortisol is shown to give rise to falsely high values when performed with the recommended optical arrangement. By exciting at 470 nm, however, results are obtained that correlate well (r = 0.972) with those of competitive protein binding. The source of the interference is not identified, but it is related to bo...

A simplified fluorometric method for determination of plasma methotrexate.

A FLUOROMETRIC METHOD for the determination of pteroylglutamic acid (PGA) in nonbiologic material was reported by Alifrey et al (1). Freeman (2) adapted this method for the determination of amethopterm in plasma. Both procedures oxidized PGA or amethopterin with permanganate to yield a strongly fluorescent substance, 2-amino-4hydroxypteridine-6-carboxylic acid (3). The fluorescence due to the l...

Transcortin: a corticosteroid-binding protein of plasma. V. In vitro inhibition of cortisol metabolism.

Additional observations on hydrochlorothiazide interference with measurement of total urinary placental estrogens.

1. Mattingly, D., A simple fluorometric method for the estimation of free il-hydroxycorticoids in human plasma. J. Clin. Pathol. 15,374(1962). 2. Sweat, M. L., Sulfuric acid induced fluorescence of corticosteroids. Anal. Chem. 26,773(1954). 3. Rubin, M., Fluorometry and phosphorimetry in clinical chemistry. Advan. Gun. Cltem. 13, 163 (1970). 4. Van de Vies, J., Individual determination of corti...