A new fluorogenic substrate, 4 methylumbelliferyl beta-D-6-sulphogalactoside, was used for the assay of galactose-6-sulphate sulphatase activity in chorionic villi, cultured villus cells, and amniocytes. The fluorometric assay is much more convenient than the conventional assay using radiolabelled, sulphated oligosaccharides. Both types of substrate were used in the prenatal diagnosis of three ...

We describe a fluorometric procedure, with use of fluorescamine, for determining plasma amino nitrogen in a 10-mul sample of deproteinized plasma. Values for apparently healthy human subjects agree well with those obtained by spectrophotometry. The simplicity and speed of the assay recommends it as a screening procedure for detecting aminoacidopathies.

A fluorometric assay for free erythrocyte porphyrins (FEP) is described in detail, the direct test being used for the analysis of blood specimens collected with anticoagulants and the spot test for analysis of blood specimens collected on filter paper. A method for determining the amount of blood absorbed by different lots of filter paper is described.

Ozone is widely used for sterilization, deodorization, and cleaning. However, the effects of ozone on human are not well understood, because there is currently no reliable assay method for ozone. Therefore the accurate measurement of ozone is important for its safe use. Here, we report optimized conditions for use with fluorescein derivative 1 (probe 1). Under optimum conditions, probe 1 reacte...

Convenient drug-resistance testing of viral mutants is indispensable to effective treatment of viral infection. We developed a novel fluorometric assay for phenotypic differentiation of drug-resistant mutants of human immunodeficiency virus-I protease (HIV-PR) which uses enzymatic and peptide-specific fluorescence (FL) reactions and high-performance liquid chromatography (HPLC) of three HIV-PR ...

The emergence and transmission of multidrug-resistant tuberculosis (MDR-TB) and extensively drug-resistant tuberculosis (XDR-TB) have raised concern about diagnostic delay associated with culture-based drug susceptibility testing methods. The association between rifampin resistance and MDR-TB or XDR-TB makes it an important genetic marker for genotypic drug susceptibility testing. In this artic...

In pursuing quantitative histochemical investigations aimed at demonstrating the biochemical architecture of human frontal cortex (l-4), we found it necessary to determine ganglioside sialic acid in submicrogram amounts. Even when adapted to the microscale, spectrophotometric methods lack the sensitivity required for studying nervous tissue samples containing less than 0.3 pg of sialic acid. Si...

A continuous and real-time fluorometric assay for monoamine-preferring phenol sulfotransferase (SULT1A3) was developed. The methodology was based on the coupling of SULT1A1 to regenerate 3'-phosphoadenosine-5'-phosphosulfate (PAPS) using 4-methylumbelliferyl sulfate (MUS) as a sulfuryl group donor. The fluorophore product (4-methylumbelliferone, MU) was continuously produced and monitored when ...

Sucrose has been found to decrease the fluorescence observed during the standard fluorometric assay of tryptophan. The quenching is enhanced with increasing concentrations of sucrose. This phenomenon is not due to a metal contaminant in the sucrose, nor to a direct interaction of the sugar with the fluorophore, norharman, which results from the oxidation of a tryptophanformaldehyde complex by F...

This method for rapid plasma ammonia determination, supplied in the form of a commercially available kit, is based on a combination of enzymic reaction and fluorometry. Concentrations up to 350 mumol/L can be measured. The detection limit is 15 mumol/L. Intra-assay coefficients of variation for 30 and 100 mumol/L concentrations were 5.0% and 3.0%, respectively. The corresponding interassay CVs ...