With the advent of potein sequence data the world has experienced a remarkable leap in scientist's interest to study proteins in a time dependent and stress dependent manner. With sequence and structural information rolling up newer mysteries regarding cellular milieu, whole protein study has become important in numerous applications such as exploring new biomarkers, diagnising diseases in vitro, identifying interaction partners, establishing cellular signaling pathways etc. Already significant advancements has been achieved in cancer research and toxicological study. In order to make up to the growing demand for proteomic studies, techniques such as 2-DE, ICAT, ESI, MALDI, SELDI and newer modifications of these techniques has too evolved in both technicalities and specific applications. The scopes of this book rest in elucidating the current developments in proteomic approach, techniques and applications. Today the burgeoning field of proteomics augurs a massive push in the limits as far as technological sensitivity, specificity and efficiency is concerned; proteomics will find its extensive application in Genomics, Transcriptomics and Metabolomics more and more for sure.