Phase separation between nucleoid and cytoplasm in Escherichia coli as defined by immersive refractometry.

摘要: The refractive indices of nucleoid and cytoplasm in Escherichia coli were derived theoretically experimentally. For the theoretical estimates, we made use known macromolecular composition E. B/r (G. Churchward H. Bremer, J. Theor. Biol. 94:651-670, 1982) estimates cell volumes. These obtained from micrographs living bacteria with a confocal scanning light microscope. values calculated, assuming that all DNA occurred protein RNA cytoplasm. Comparison experimental index directly by immersive refractometry showed that, besides its DNA, must contain an additional amount solids equivalent to 8.6% (wt/vol) protein. With containing 6.8% 21% 4% RNA, mass difference is obtained, which accounts for phase separation observed between cells phase-contrast microscopy. decrease relative upon, instance, OsO4 fixation was interpreted as being indicative loss content nucleoid. Images