New colorimetric method for quantitative determination of protein in urine.
Total urinary protein is rapidly precipitated at room temperature by tannic acid. The tannic acid/protein precipitate, dissolved in aqueous triethanolamine/ferric chloride solution, gives a purple-violet color of high absorptivity. Absorbance at 510 nm is linearly related to concentration from 0.05 to 1.50 A for a protein content of 0.05 to 1.50 g/liter, and less than 5 mg/liter can be detected. The CV and analytical recovery ranged from 0.5 to 1.8% and 98 to 103%, respectively. Nonprotein urinary constituents do not interfere.
D000293:Adolescent; D000328:Adult; D000368:Aged; D011232:Chemical Precipitation; D003124:Colorimetry; D005260:Female; D005290:Ferric Compounds; D006801:Humans; D047348:Hydrolyzable Tannins; D008297:Male; D008722:Methods; D008875:Middle Aged; D011507:Proteinuria / Q000652:urine*
D005290:Ferric Compounds; D047348:Hydrolyzable Tannins