Measurement of Albumin in the Sera of Patients

FRACTIONATIONAlbumin is the serum protein most often measured in clinical chemistry.Estimations of serum levels can be of value in patients with various protein losing states, cirrhosis, and myelomatosis.This bulletin comprises an evaluation and comparison of methods.Many methods are available for the determination of albumin levels in body fluids, depending on a wide variety of the physical and chemical properties of albumin.Although it is in patients with the diseases already mentioned that accurate albumin estimations are particularly required for diagnosis and management, most of these methods have been assessed with normal human serum only.Many methods giving satisfactory or apparently satisfactory results with normal sera may be misleading when used to evaluate pathological sera.The albumin methods are therefore discussed with particular reference to estimations on pathological sera and are considered under the headings of salt fractionation, dye binding (a) after electrophoresis and precipitation and (b) in solution by spectral shift, and immunochemistry.The problems associated with each method are discussed and the results of albumin estimation compared by all these methods in 20 normal subjects and 46 patients with cirrhosis, nephrosis, and paraproteinaemias, The results compared to those obtained by an immunochemical method are shown in table 3, and they demonstrate the unsuitability of many of these techniques for the estimation of albumin in abnormal sera.In all of the following studies we have used Behringwerke ORHA 04 human albumin standard, shown by electrophoresis and two dimensional immuno-electrophoresis against anti-whole human serum to contain no detectable protein impurities.This standard was calibrated by the absorption of ultraviolet light using the specific extinction coefficient Ef8~m 5.80 for a 1 g{100 ml solution (SchOnenberger, 1955).