Invalid measurement of plasma albumin using bromcresol green methodology in penguins (Spheniscus species).
ABSTRACT The purpose of this study was to examine the validity of albumin determinations in penguin plasma by the bromcresol green (BCG) method and the gold standard of protein electrophoresis (EPH). Plasma from 96 clinically normal and abnormal penguins (Spheniscus species) was analyzed. The 2 methods did not yield equivalent results. The BCG method underestimated the albumin level in samples from normal patients (indicated by a normal albumin:globulin ratio) and overestimated the albumin level in samples from clinically abnormal penguins (indicated by a decreased albumin:globulin ratio). After EPH of plasma samples from clinically abnormal penguins samples was performed to separate albumin and globulin fractions, the globulins exhibited marked binding to the BCG dye. There were no significant differences between the variable reaction of paired serum and plasma samples when using the BCG method. These results demonstrated marked differences in the determination of albumin levels when using the BCG method and protein EPH. They further demonstrated that the BCG method can provide erroneous results, which have the potential to significantly impact clinical diagnosis and treatment. This study confirmed findings from previous studies in other avian species that the BCG method yields unreliable results in avian species. It is our conclusion that the BCG method, commonly found on automated analyzers in commercial laboratories and on point-of-care analyzers, should not be used to determine albumin concentration in avian samples.
Annals of Clinical Biochemistry 12/1985; 22 ( Pt 6):565-78. · 2.17 Impact Factor
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ABSTRACT: A rapid and reliable method for measuring serum albumin employing bromcresol green is described. The addition of albumin to a solution of bromcresol green in a 0.075 M succinate buffer pH 4.20 results in an increase in absorbance at 628 nm. The absorbance-concentration relationship is linear for samples containing up to 6 g/dl albumin. Bilirubin, moderate lipemia, and salicylate do not interfere with the analysis. The use of nonionic surfactant (Brij-35) reduces the absorbance of the blank, prevents turbidity and provides linearity. The results by this method agree very well with those obtained by electrophoresis and salt fractionation. The method is simple, it has excellent precision and the reagents are stable. A protein standard is introduced which can be employed for both the total serum proteins and albumin determinations.Clinica Chimica Acta 03/1997; 258(1):21-30. · 2.54 Impact Factor
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ABSTRACT: We describe a new automated dye-binding method for serum albumin determination with bromcresol purple (BCP) that has several advantages over an existing bromcresol green (BCG) method. The continuous-flow method is sensitive, linear, and precise, with negligible sample interaction at an analytical rate of 60 samples per hour. Unlike BCG, BCP did not react with an albumin-free serum globulin preparation or pure human transferrin solutions. Reaction with serum was instantaneous; in contrast, BCG exhibits a slow nonspecific reaction with some specimens. The specificity of BCP was demonstrated by good agreement with results of "rocket" immunoelectrophoresis (EIA) where y(BCP) = 0.95X(EIA) + 1.72. The BCG method overestimated serum albumin concentration where y(BCG) = 1.01X(EIA) + 6.77. Precipitation, which affects the BCG method, was not observed with BCP. Blank corrections were negligible, salicylate did not interfere, and bilirubin affected the method only if present in very high concentration. The method offers a solution to the poor accuracy of existing BCG methods while retaining many of their desirable features.Clinical Chemistry 02/1978; 24(1):80-6. · 7.91 Impact Factor