A fluorometric method for the determination of phenylpyruvic acid (PPA) has been established. Benzaldehyde formed from PPA by alkaline decomposition is quantified by means of its fluorogenic reaction with 1,4-dimethyl-3-carbamoylpyridinium chloride. PPA can be determined in the range of 0.1-3 nmol/50 ƒÊl with the relative standard deviation of 4.0-4.1%. About 70% recovery was obtained when a ur...

Resorufin (1) has been found to act as an electron acceptor in glucose oxidase (GOD)-catalyzed oxidation of glucose. When a 1: 1: 1 mixture of solutions of 1 (5.0 microM), glucose, and GOD (4.0 mg/ml) in phosphate buffer (pH 7.4, 0.1 M) was incubated at 36 degrees C under aerobic conditions and the reaction was followed by a measurement of changes in fluorescence intensity due to 1, only two ty...

Mellors et al. ( 1 ) h a v e found by means of microfluorometry that an approximately linear relation exists between the fluorescence intensity of cell nuclei stained with berberine sulfate and their nucleic acid content. However, very little is known as to the interaction between nucleic acids and berberine sulfate in vitro. The purpose of the present study is to examine this interaction in vi...

We describe a routine method for determining plasma concentrations of quinidine by liquid chromatography. The procedure requires 1.0 ml of plasma (or serum) and involves internal standard addition, extraction with ether, and separation on a column of microparticulate silica. Day-to-day CV (15 days) was less than 5% and no deterioration in column performance has been observed during 12 months. C...

OBJECTIVE Easy tool for newborn screening of Gaucher and Hurler diseases. METHODS Method comparison between fluorometric enzymatic activity assay on a digital microfluidic platform and micro-titer plate bench assay was performed on normal (n = 100), Gaucher (n = 10) and Hurler (n = 7) dried blood spot samples. RESULTS Enzymatic activity analysis of glucocerebrosidase (Gaucher) and α-l-iduro...

The effect of the administration of a synthetic peptide with corticotrophic properties (18-ACTH) on the plasma corticosteroid levels of 72 healthy volunteers was studied. The same effect is seen both after subcutaneous and intramuscular injection. Intravenous administration provokes a longer lasting influence on adrenocortical activity, especially when large doses of the peptide are given; side...

Three procedures have been compared for monitoring heparin in patients undergoing cardiopulmonary bypass: (1) activated clotting time (ACT) (2) protamine titration, and (3) fluorometric substrate assay. The ACT monitors the degree of anticoagulation. It is easy to perform and is relatively inexpensive, however, it does not correlate well with heparin levels and may not accurately predict the pr...

A review of indirect photometric and fluorometric detection in high-performance liquid chromatography (HPLC) is presented. A functional definition of indirect detection, somewhat broader and simpler than what was often used to characterize these techniques, was employed for this review. Emphasis was placed on distinguishing different approaches to indirect photometric and fluorometric detection...