Proteins are the molecules that are responsible for the majority of functions inside the cell. Thus scientists are usually most interested in which proteins and how much of each protein are present in a cell following a particular experimental manipulation. Unfortunately, it is difficult to study global protein expression, since proteins cannot be replicated easily in the lab. Also, proteins do not have complementary sequences like DNA or RNA that can be used as probes. For this reason, many scientists rely on gene expression analysis to give clues as to how a protein is being regulated. However, new technologies that…