Single-Molecule Localization Microscopy with the Fluorescence-Activating and Absorption-Shifting Tag (FAST) System

ACS Chem Biol. 2019 Jun 21;14(6):1115-1120. doi: 10.1021/acschembio.9b00149. Epub 2019 May 23.

Abstract

We develop and employ the Fluorescence-Activating and absorption-Shifting Tag (FAST) system for super-resolution (SR) imaging and single-molecule tracking based on single-molecule localizations. The fast off rate of fluorogen binding, combined with its spatially well-separated labeling of the densely expressed FAST fusion proteins, allowed single-molecule measurements to be performed in both living and fixed cells. The well-separated fluorescence localization density was achieved by either reversibly controlling the fluorogen concentration or by irreversibly photobleaching the FAST-fluorogen complex. The experimentally determined resolution of 28 nm allowed us to resolve Ensconsin-labeled microtubules and to track single molecules in mitochondria. Our results demonstrate that FAST is well-suited for single-molecule localization microscopy (SMLM). The small size and the availability of spectrally distinct fluorogens present unique advantages of the FAST system as a potential orthogonal labeling strategy that could be applied in conjunction with existing super-resolution dyes and photoactivatable proteins in versatile imaging applications.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Cell Line, Tumor
  • Chemistry
  • Fluorescent Dyes / chemistry*
  • Humans
  • Microscopy, Fluorescence / methods*
  • Microtubules / metabolism
  • Photobleaching
  • Single Molecule Imaging / methods*

Substances

  • Fluorescent Dyes