Evaluation of direct grafting strategies via trivalent anchoring for enabling lipid membrane and cytoskeleton staining in expansion microscopy

Research output: Contribution to journalArticle

Authors

  • Gang Wen
  • Marisa Vanheusden
  • Aline Acke
  • Donato Valli
  • Volker Leen
  • Johan Hofkens

Colleges, School and Institutes

External organisations

  • KU Leuven

Abstract

Super-resolution fluorescence microscopy is a key tool in the elucidation of biological fine structures, providing insights into the distribution and interactions of biomolecular complexes down to the nanometer scale. Expansion microscopy is a recently developed approach for achieving nanoscale resolution on a conventional microscope. Here, biological samples are embedded in an isotropically swollen hydrogel. This physical expansion of the sample allows imaging with resolutions down to the tens-of-nanometers. However, because of the requirement that fluorescent labels are covalently bound to the hydrogel, standard, small-molecule targeting of fluorophores has proven incompatible with expansion microscopy. Here, we show a chemical linking approach that enables direct, covalent grafting of a targeting molecule and fluorophore to the hydrogel in expansion microscopy. We show application of this series of molecules in the antibody-free targeting of the cell cytoskeleton and in an example of lipid membrane staining for expansion microscopy. Furthermore, using this trivalent linker strategy, we demonstrate the benefit of introducing fluorescent labels post-expansion by visualizing an immunostaining through fluorescent oligonucleotide hybridization after expanding the polymer. Our probes allow different labeling approaches that are compatible with expansion microscopy.

Details

Original languageEnglish
JournalACS Nano
Early online date16 Mar 2020
Publication statusPublished - 26 Mar 2020

Keywords

  • expansion microscopy, trifunctional linker, lipid membranes, actin filaments, post-expansion labeling