Comparison of Different Albumin Removal Methods for Evaluation of Human Serum Proteome

Proteomics examines the protein content of a cell, tissue or physiological fluid in certain developmental or pathological conditions. Serum, a rich source of protein, is easily accessible and represents the physiological and clinical status of individuals. Emergence of a disease can cause qualitative and quantitative changes in the concentration of certain proteins in the serum. Nevertheless, separation and examination of low abundance proteins at presence of high abundance proteins such as albumin and immunoglobulin, which comprise over 60% of total protein, are limited. In this experimental study, in order to remove albumin, serum samples from four different removal methods including two trichloroacetic acid (TCA) precipitation, ammonium sulfate fractionation and using specific kits to remove albumin and immunoglobulin were compared. The results indicated that precipitation and fractionation techniques considerably remove albumin. Due to its specific performance, using kit removes larger amounts of albumin and immunoglobulin. However, the protein patterns derived from different albumin removal methods were different. It is suggested that several albumin removal methods should be used during the examination of serum protein content.