Abstract-Genomic and proteomic approaches together promise to reveal a multidimensional view of a biological system. As compared to Genomic approaches, Proteomic studies have their fair amount of limitations. The technical issues troubling proteomic approaches include gel-to-gel reproducibility, biases toward identifying similar proteins in unrelated proteomic studies, and reliability of protein extraction methods. Many types of information cannot be obtained from the study of genes alone because proteins not genes are responsible for the phenotypes of cells. Mechanisms of disease, aging and the effects of the environment cannot be explained solely by the genome because through the study of proteins can protein modifications be analyzed and the targets of drugs of identified.