Protein Analysis and Characterization

Proteins differ from each other in their size, molecular structure and physiochemical properties. These differences allow for protein analysis and characterization by separation and identification. Separation is typically done via electrophoresis where proteins are differentiated by size or mass, and isoelectric focusing, where protein are separated by charge. These techniques can be done independently, or in combination- referred to as 2D electrophoresis. Equipment for separation includes polyacrylamide gels, organic stains, electrophoresis boxes, isoelectric focusing immobilized strips, 2D electrophoresis equipment, and protein standards. Identification is done via mass spectrometry where molecules are ionized to determine their mass to charge ratios. Mass spectrometry equipment includes protein fractionators, GC/MS, LC/MS, CE/MS and time of flight systems. Identification can also be done via amino acid sequencing by Edman degradation, crystal imaging and surface plasmon resonance. With so many options available, laboratories typically will employ multiple strategies for protein analysis and characterization.