Abstract
The non-destructive collection of ultrathin sections on silicon wafers for post-embedding staining and volumetric correlative light and electron microscopy traditionally requires exquisite manual skills and is tedious and unreliable. In MagC introduced here, sample blocks are augmented with a magnetic resin enabling the remote actuation and collection of hundreds of sections on wafer. MagC allowed the correlative visualization of neuroanatomical tracers within their ultrastructural volumetric electron microscopy context.
Highlights
The ultrathin physical ablation of sample blocks is a prerequisite for volumetric biological electron microscopy (EM)
A piece of this resin was glued with an epoxy that is usually used for EM studies to a sample block of interest, with the help of a small mechanical device (Figure 1—figure supplement 3), thereby maintaining the position of the blocks during curing in an oven
Since the introduction of Array Tomography in 2007 by the Smith laboratory (Micheva and Smith, 2007), volumetric postembedding correlative light and electron microscopy has been performed on manually collected ultrathin sections on flat substrates
Summary
The ultrathin physical ablation of sample blocks is a prerequisite for volumetric biological electron microscopy (EM). The destructive methods, serial block face (Denk and Horstmann, 2004) and focused ion beam EM (Knott et al, 2008), enable serial access to the sample in its whole depth only very briefly and inside the vacuum chamber of a specialized scanning EM, prohibiting the (re-) imaging of permanently destructed portions, liquid treatments such as heavy-metal poststaining or immunostaining (Micheva and Smith, 2007), fluorescent light microscopy (LM) (Sigal et al, 2015), and various nanoscale imaging techniques (Pirozzi et al, 2018). The automated non-destructive tape-based ablation method ATUM (Kasthuri et al, 2015), which has greatly benefited volumetric EM (Kornfeld and Denk, 2018), provides sections on silicon wafers but at a low packing density (about 200 per 100 mm diameter wafer), through an intermediate tape, and after manual gluing onto a wafer. Other non-destructive collection approaches require excellent ultramicrotomy skills and intense monitoring of ribbons during sectioning and collection onto flat substrates (Horstmann et al, 2012; Spomer et al, 2015; Burel et al, 2018; Koike et al, 2017; Smith, 2018; Templier and Hahnloser, 2019)
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call