Detection and identification of bacterial cell surface proteins by fluorescent labeling.

A rapid method of detection and identification of bacterial cell surface proteins is needed to better understand the interaction of bacteria with host components. To detect cell surface proteins, we have labeled cells of the Gram-negative anaerobic bacterium, Porphyromonas gingivalis, with fluorescent cyanine dyes, Cy3 and Cy5. We demonstrate that only cell surface proteins were labeled, indicating the method applied in our study is suitable for detection and identification of cell surface proteins in Gram-negative bacteria and possibly other organisms.