Albuminometer

Albuminometer, a device for the quantitative determination of protein in urine, the Esbach albuminometer consists of a glass test tube with a conical end having two marks with the letters B and U. At the bottom, near the conical end, there are divisions of albumin corresponding to the numbers. The test tube is filled to the mark U with urine, to the mark R with Esbach's reagent, closed with a rubber stopper, and mixed. The reagent for precipitating protein consists of 20 g of citric acid, 10 g of picric acid, and 970 cm³ H₂O. After 24 hours the coagulated protein settles, and the divisions on the tube directly indicate the amount of protein in 1,000 cm³ of the liquid taken for analysis. The urine before mixing with the protein-precipitating reagent must have an acidic reaction and not too high specific gravity. With a significant content of protein the urine is diluted 2–4 times. Dilution is also necessary when determining protein in exudates and transudates.