The Assay of Urinary Peptides Using a Biuret Reagent

[摘要] The components of a biuret reagent have been investigated to minimize variations in readings resulting from small variations in composition. When this biuret reagent is used for the assay of urinary peptides, readings should be made at 405 mµ. There is a limited but adequate straight-line relationship between concentration and absorbance on normal urine. Urine from convalescing burn patients containing normal concentrations of peptides may read 10-20 per cent low.This method has a coefficient of variation of 1.68 per cent. Under ordinary circumstances there will be no interference from oxalic acid, creatinine, uric acid, ammonia, or hippuric acid. Amino acids and glucose may result in false elevations of readings. Samples must be preserved by refrigeration or with toluene or thymol, and when so treated are stable up to 48 hours for peptide assay.

[学科分类] 过敏症与临床免疫学