RESEARCH PROFILE: Molecule counting made easy

摘要

Technical limitations have thwarted researchers from achieving the holy grail of protein analysis: quantitative analysis of rare proteins in complex biological sera. But in a new AC paper (2009, DOI 10.1021/ac901068x), Robi Mitra and colleagues at the Washington University St. Louis School of Medicine and Helicos Biosciences describe the counting of single molecules from both purified protein solutions and rabbit serum on a surface with low background using fluorescently labeled antibodies. The first step, according to Mitra, was to find a good surface for immobilizing proteins that also minimized nonspecific adsorption of antibodies. "We did a systematic search of the literature," Mitra explains, to look for the best noninteracting surfaces. Then, "we did a systematic comparison" of 12 surfaces.