title: 4Pi-confocal microscopy of live cells.
abstract: By coherently adding the spherical wavefronts of two opposing lenses, two-photon excitation 4Pi-confocal fluorescence microscopy has achieved three-dimensional imaging with an axial resolution 3-7 times better than confocal microscopy. So far this improvement was possible only in glycerol-mounted, fixed cells. Here we report 4Pi-confocal microscopy of watery objects and its application to the imaging of live cells. Water immersion of 4Pi-confocal microscopy of membrane stained live Escherichia coli bacteria attains a 4.3-fold better axial resolution as compared to the best water immersion confocal microscope. The resolution enhancement results into a vastly improved three-dimensional representation of the bacteria. The first images of live biological samples with an all-directional resolution in the 190-280 nm range are presented here, thus establishing a new resolution benchmark in live-cell microscopy.
authors.affiliation: High Resolution Optical Microscopy Group, Max-Planck-Institute for Biophysical Chemistry, Göttingen, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Bahlmann
authors.forename: S
authors.initials: S
authors.lastname: Jakobs
authors.forename: S W
authors.initials: SW
authors.lastname: Hell
mesh_terms: D004926:Escherichia coli / Q000648:ultrastructure; D018613:Microscopy, Confocal