Diverse protocols for correlative super-resolution fluorescence imaging and electron microscopy of chemically fixed samples

Nat Protoc. 2017 May;12(5):916-946. doi: 10.1038/nprot.2017.017. Epub 2017 Apr 6.

Abstract

Our groups have recently developed related approaches for sample preparation for super-resolution imaging within endogenous cellular environments using correlative light and electron microscopy (CLEM). Four distinct techniques for preparing and acquiring super-resolution CLEM data sets for aldehyde-fixed specimens are provided, including Tokuyasu cryosectioning, whole-cell mount, cell unroofing and platinum replication, and resin embedding and sectioning. The choice of the best protocol for a given application depends on a number of criteria that are discussed in detail. Tokuyasu cryosectioning is relatively rapid but is limited to small, delicate specimens. Whole-cell mount has the simplest sample preparation but is restricted to surface structures. Cell unroofing and platinum replication creates high-contrast, 3D images of the cytoplasmic surface of the plasma membrane but is more challenging than whole-cell mount. Resin embedding permits serial sectioning of large samples but is limited to osmium-resistant probes, and is technically difficult. Expected results from these protocols include super-resolution localization (∼10-50 nm) of fluorescent targets within the context of electron microscopy ultrastructure, which can help address cell biological questions. These protocols can be completed in 2-7 d, are compatible with a number of super-resolution imaging protocols, and are broadly applicable across biology.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, N.I.H., Intramural

MeSH terms

  • Biological Products / analysis*
  • Cytological Techniques / methods*
  • Microscopy, Electron / methods*
  • Optical Imaging / methods*

Substances

  • Biological Products