Simple spectrophotometric determination of urinary albumin by dye-binding with use of bromphenol blue.

Abstract

This procedure for routine quantification of albumin in urine is based on the dye-binding properties of albumin with bromphenol blue. The absorbance of 100 microL of urine mixed with 3 mL of color reagent is measured against blank reagent at 610 nm after 30 s. Results vary linearly with albumin concentration up to 6 g/L. The reaction is pH independent in the physiological range. It is not subject to substantial interference by uric acid, creatinine, calcium, sodium chloride, or bilirubin. The presence of globulins produces a small positive error. Within-run precision (CV) was 4.8, 1.5, and 0.9%, and day-to-day precision was 11.2, 2.0, and 1.9%, for samples containing albumin at about 0.1, 1.0, and 6.0 g/L, respectively. Results by a radial-immunodiffusion method (x) correlated well with those by the proposed method (y): r = 0.986; y = 0.98x + 0.096; n = 64. The method can also be used to detect globulins, such as Bence Jones protein, by measuring the ratio of the absorbance at 30 min to that at 30 s.

Modified Bromophenol Blue Dye Binding Method for Quantitation of Microalbuminuria in Diabetes Mellitus

“…The method has been found to have a good precision as is evident from low coefficients of variation. In comparison to the precision study reported [5] this method shows more precision (Table 2) at the lower concentration of albumin employing 1:5 ratio of urine(sam-pIe) and reagent. The mean values observed in normals are higher than reported (6)(7)(8) though within the suggested normal range.…”

“…The mean values observed in normals are higher than reported (6)(7)(8) though within the suggested normal range. This could be due to some positive bias be› cause of various non-protein constituents of urine, or globulins if present [5). This needs further study.…”

“…Ten mL of well-mixed urine was centri› fuged for 10 min at 1500 rpm and the super› nate was analyzed for albumin by a modified bromophenol-blue (BPB) dye-binding method [5]. The BPB reagent was prepared by dissolving 125.7 mg BPB in 3 mL of 0.1 mollL NaOH.…”

Development of Broad-Spectrum Antimicrobial Latex Paint Surfaces Employing Active Amphiphilic Compounds

“…Bromophenol blue has been used extensively to quantify the amount of protein or peptide in a solution. , A test method to visualize surface peptide using bromophenol blue was adapted from these solution test methods and was employed as previously noted . Approximately 4.5% of Chr-1 and 1% of Chr-3 was present at the coating surface.…”

EVALUATION OF THE CYTOTOXIC EFFECTS INDUCED BY 68Ga-NODAGA-c(RGDfK) AND 68Ga-DOTA-c(RGDfK) IN MURINE MALIGNANT MELANOMA

“…Biochemical Assays: The cells were lysed in a lysis buffer containing 50 mM Tris-HCl (pH 7.5), 150 mM NaCl, 0.1% SDS, 1% TritonX-100, and 1% sodium deoxycholate with sonication (20 kHz, 10 s, twice) in an ultrasonic homogenizer (UH-50, Tokyo, Japan). Lipid peroxidation products were measured using thiobarbituric acid reactive substances (TBARS reaction) and total thiols were monitored by Schosinsky assay [13]. Spectrophotometric assays were performed with the AnalyticYena spectrophotometer and the winASPECT software (Yena, Germany).…”