We describe an immunoassay for thyroxine in serum. In the assay specific antibody covalently bonded to latex particles is used, along with horseradish peroxidase as the label, and o-phenylenediamine as the chromogen. The flexible protocol is designed for manual execution. Performance is similar to that of the highest-sensitivity thyroxine radioimmunoassays. Results correlate well with radioimmu...

We evaluated the efficacies of five treatment procedures for eliminating ascorbate interference in the enzymatic determination of urinary oxalate. Aliquots of urine samples, containing different amounts of added ascorbate and oxalate, were individually subjected to ferric chloride, sodium nitrite, sodium periodate, charcoal, or ascorbate oxidase treatment to eliminate ascorbate interference. Ox...

Visualization of the neuronal tract tracer horseradish peroxidase (HRP) is commonly achieved through the histochemical detection of its enzymatic activity using 3,3',5,5'-tetramethylbenzidine (TMB) as a chromogen. However, the TMB product is unstable and is incompatible with tissue processing methods that render the enzyme inactive, or when a combination of HRP tract tracing with neuronal pheno...

INTRODUCTION Copper is essential micronutrient and has an important role in the human body. The serum copper increases during pregnancy and is doubled at full term. Lower levels of serum copper in pregnancy are connected with some pathological conditions. OBJECTIVE The aim of this study was to estimate the levels of serum copper in normal and pathological pregnancies, comparing them with valu...

Direct selective detection of erythrosine in saffron in the presence of other synthetic dyes considers its fluorescence at 532 nm excitation/548 nm emission. Saffron pre-treatment was according to the ISO 3632-2 trade standard test methods. On account of calculated quantum yield values, none of the yellow dyes is expected to interfere. Among red ones, reservations about allura red AC, azorubine...

We performed a quantitative analysis of M and P cell mosaics of the common-marmoset retina. Ganglion cells were labeled retrogradely from optic nerve deposits of Biocytin. The labeling was visualized using horseradish peroxidase (HRP) histochemistry and 3-3'diaminobenzidine as chromogen. M and P cells were morphologically similar to those found in Old- and New-World primates. Measurements were ...

AIMS To develop and immunohistochemical staining method for cryostat and paraffin wax sections so that two different antigens in the same section of tissues could be detected by combining immunoenzyme and immunofluorescence techniques. METHODS This double immunohistochemical staining method combines alkaline phosphatase-anti-alkaline phosphatase (APAAP) using New Fuchsin as a chromogen and in...

The dinitrophenylhydrazine method for the determination of ascorbic acid is based upon treatment with 85% HzS04 of the chromogen formed by the coupling of 2,4-dinitrophenylhydrazine with oxidized ascorbic acid. In the original publication of this method, Roe and Kuether (1) set the temperature of the coupling reaction at 37” and used a 3-hour incubation period. These authors showed that a low t...

Although the clearance of endogenous creatinine as a measure of the glomerular filtration rate has been much criticized, it remains the only possible measure where repeated or continuous investigation is needed, and has already yielded much useful information. When we started to use it, however, it became apparent that while the estimation of creatinine in urine was satisfactory, that of plasma...

Purpose: To develop and validate a spectrophotometric method for the quantitative determination of eflornithine hydrochloride as a pure compound and in pharmaceutical formulations. Methods: The method involved the reaction of the target compound with vanillin reagent at specific pH 5.6 to produce a green reddish color chromogen. The derivative chromogen exhibits absorption maxima at 578 nm. At ...