Direct Spectrophotometric Determination of Albumin in Human Serum

Abstract

In a convenient and direct method for determination of albumin in human serum, based on the decrease in absorbance of a neutral buffered solution of bromcresol green when albumin combines with the indicator, serum is diluted with a solution of bromcresol green of sufficient concentration to allow essentially linear change of absorbance with albumin concentration. Measurements are made at 615 mµ, where the absorbance of hemoglobin or bilirubin does not interfere. Extremely lipemic, turbid serums may be accurately analyzed. This method has been applied to a number of abnormal serums and compared with measurements of the albumin fraction of serum which is soluble in 2% (w/v) TCA in ethanol. Satisfactory agreement was obtained. Tests indicated that bromcresol green was not bound by serum globulins.