Detect the motion of green fluorescence proteins within living cell

摘要

Single-molecule/particle tracking technology is becoming a powerful tool to the noninvasive study of membrane property and membrane molecular processes. Here, we used total internal reflection fluorescence microscopy combined with oblique illumination fluorescence microscopy to investigate green fluorescence protein within living cell. Total internal reflection illumination allowed the observation of molecules in the cell membrane of living cell since the penetrate depth is adjusted to about 100nm, and oblique illumination is allowed the observation of molecules/particles both in the cytoplasm and apical membrane, which suggested this combination would be promising to investigate protein dynamics through the whole cell. Not only individual protein molecule/particle tracks have been analyzed quantitatively to reveal the motion of protein, but also statistical analysis has been done to substantiate the observation of protein dynamics. Our data that involved up to 700 trajectories in several hundreds cells are indicated that at least four modes of motion are presented, that is directed motion, normal diffusion (random walk), binding motion and corralled motion.rnDetailed analysis as well as statistical analysis is presented in the paper.