Albumin in urine

Trichloroethanoic acid, CCI3COOH. A crystalline solid which rapidly absorbs water vapour m.p. 58°C, b.p. 196-5" C. Manufactured by the action of chlorine on ethanoic acid at 160°C in the presence of red phosphorus, sulphur or iodine. It is decomposed into chloroform and carbon dioxide by boiling water. It is a much stronger acid than either the mono- or the dichloro-acids and has been used to extract alkaloids and ascorbic acid from plant and animal tissues. It is a precipitant for proteins and may be used to test for the presence of albumin in urine. The sodium salt is used as a selective weedkiller. 

Increased albumin usually indicates glomerular injury, although it is not a specific marker for any one nephron site (Guder and Hofmann 1992 Price et al. 1996 Finn and Porter 1998). High levels of albumin in urine are invariably the result of glomerular malfunction. Low level increases in urine albumin, especially in circumstances where total urine protein excretion is not elevated ( microalbuminuria ) can result either from increased glomerular filtration or decreased tubular reabsorption, and albumin values... 

On the basis of the split-peak equations, Hage et al. I8) developed a model to interpret competitive binding immunoassays and applied the method to the determination of low levels of albumin in urine 47). An equation was derived to predict the assay response as a function of flow rate, amounts of analyte and... 

As many reports have shown, there remains a tremendous amount of information in the low-MW fraction of biological samples such as serum or urine. Serum or plasma may be divided into a high-MW and a low-MW fraction by ultrafiltration or SEC. Nevertheless, even ultrafiltration at a cut-off of 10 kDa still leaves a considerable amount of albumin in urine or in ultrafiltered serum, since the MW cut-off is not sharp as may be related to the distribution of the pore sizes. 

Chesham J, Anderton SW, Kingdon CF. Rapid, competitive enzymoimmunoassay for albumin in urine. Chn Chem 1986 32 669-71. 

Gatling W, Shaw KM, et al. Assessment of immunochemical methods for determining low concentrations of albumin in urine. Clin Chem 1986 32 ... 

Detection and Determination of Albumin in Urine.—If the urine be not perfectly clear it is filtered if this do not render it perfectly transparent, it is treated with a few drops of magnesia mixture (p. 120, note), and again filtered. The filtrate, if alkaline, is... 

I. Various Mineral Acids,—Nitric acid is often used. If the acid is allowed to flow under a protein solution a white ring forms at the junction of the acid and the solution. This reaction, which is known as Heller s test, is a very delicate one, and is used in detecting albumin in urine. Peptones are not precipitated by nitric acid. 

Herber, R.F.M., Bernard, A., and K.H. Schaller (in press). Standardized method for the determination of /32-microglobulin, retinol binding protein and albumine in urine. Pure Appl. Chem. 

Heller s Test, which is important in the detection of albumin in urine, is carried out by placing about 2 ml. of concentrated nitric acid in a test tube, and carefully adding about 5 ml. of solution so as to form a layer on top. If a higher protein be present a white, cloudy ring forms at the junction of the liquids. 

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