Both methods gave excellent reproducibility and, particularly with the high sensitivity method, it was found that sample range could be varied by changing the sample volume aspirated and if necessary running it at 20°C, thus obviating full-scale deflection readings. The improvement in sensitivity with this method appears to result from the reaction with the phenol reagent, the initial biuret re...

A proposed heat precipitation and thrombin interaction technic for fibrinogen isolation has been compared with a sulfite fractionation technic. All three methods exhibit a high degree of correlation. Fibrinogen, which has been separated from plasma by these technics, may be quantitated by the colorimetric modified biuret and phenol-biuret reaction. For direct measurement of fibrinogen, heat pre...

We compared an immunochemical method specific for plasma proteins with a chemical method, in which interfering substances are separated by gel filtration and "total" urinary protein is determined by the biuret reaction followed by reaction of protein-bound copper with diethyldithiocarbamate after a second gel filtration to remove nonprotein-bound copper. More than 250 24-h urine samples were an...

These experiments appear to indicate that whatever substance in embryonic tissue extracts excites mitosis, and therefore would appear to be the growth-stimulating substance, is capable of passing through a collodion membrane which is impermeable to proteins, at all events in such concentration as would give rise to any biuret reaction. The substance is therefore diffusible.

PURPOSE The current study was designed to investigate the antinociceptive effects of several biuret derivatives with N, N`-diphenyl, N-phenyl-N`-alkylphenyl, N,N`-bis alkylphenyl, 2-methylquinoline-4-yl, benzo[d]thiazol-2-ylthio and (1-phenyl-1H-tetrazol-5-yl)thio substituents on the formalin-evoked pain in mice. METHODS Antinociceptive activity of the nine biurets derivatives were assessed a...

In the course of an investigation of the biochemical changes following experimental liver injury we felt the need of a simple, rapid, and accurate method for determining the protein fractions in small amounts of serum. Among the simpler procedures known, the biuret reaction seemed to offer the most encouraging possibilities. Variations and improvements in the application of the biuret reaction ...

Pesticides based on the s-triazine ring structure are widely used in cultivation of food crops. Cleavage of the s-triazine ring is an important step in the mineralization of s-triazine compounds and hence in their complete removal from the environment. Cyanuric acid amidohydrolase cleaves cyanuric acid (2,4,6-trihydroxy-s-triazine), which yields carbon dioxide and biuret; the biuret is subject ...

Glycylglycyiglycine was investigated as a reference standard for use in serum protein measurement by the biuret reaction. The tripeptide-biuret solution has a molar absorptivity of 96 at 565 nm, and absorbances at both 550 nm and 565 nm are proportional to concentration. By a manual reference procedure, the 550-nm absorbance of 1.0 g of tripeptide was equivalent to that given by 1.72 ± 0.03 g o...