title: Optical imaging of individual biomolecules in densely packed clusters.
abstract: Recent advances in fluorescence super-resolution microscopy have allowed subcellular features and synthetic nanostructures down to 10-20 nm in size to be imaged. However, the direct optical observation of individual molecular targets (∼5 nm) in a densely packed biomolecular cluster remains a challenge. Here, we show that such discrete molecular imaging is possible using DNA-PAINT (points accumulation for imaging in nanoscale topography)-a super-resolution fluorescence microscopy technique that exploits programmable transient oligonucleotide hybridization-on synthetic DNA nanostructures. We examined the effects of a high photon count, high blinking statistics and an appropriate blinking duty cycle on imaging quality, and developed a software-based drift correction method that achieves <1 nm residual drift (root mean squared) over hours. This allowed us to image a densely packed triangular lattice pattern with ∼5 nm point-to-point distance and to analyse the DNA origami structural offset with ångström-level precision (2 Å) from single-molecule studies. By combining the approach with multiplexed exchange-PAINT imaging, we further demonstrated an optical nanodisplay with 5 × 5 nm pixel size and three distinct colours with <1 nm cross-channel registration accuracy.
authors.affiliation: Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, Massachusetts 02115, USA.|Biophysics Program, Harvard University, Boston, Massachusetts 02115, USA.
authors.forename: Mingjie
authors.identifier: 0000-0002-8665-4966
authors.initials: M
authors.lastname: Dai
authors.affiliation: Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, Massachusetts 02115, USA.|Department of Systems Biology, Harvard Medical School, Boston, Massachusetts 02115, USA.
authors.forename: Ralf
authors.initials: R
authors.lastname: Jungmann
authors.affiliation: Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, Massachusetts 02115, USA.|Department of Systems Biology, Harvard Medical School, Boston, Massachusetts 02115, USA.
authors.forename: Peng
authors.initials: P
authors.lastname: Yin
mesh_terms: D004247:DNA / Q000737:chemistry* / Q000648:ultrastructure; D008856:Microscopy, Fluorescence; D057054:Molecular Imaging / Q000379:methods*; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D061848:Optical Imaging / Q000379:methods*
chemical_list: D004247:DNA