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.

SUBMITTER: Dai M 

PROVIDER: S-EPMC5014615 | biostudies-literature | 2016 Sep

REPOSITORIES: biostudies-literature