Cryo-
el
ectron tomography of vitr
eous cryo-s
ections is th
e most suitabl
e m
ethod for
exploring th
e 3D organization of biological sampl
es that ar
e too larg
e to b
e imag
ed in an intact stat
e. Producing good quality vitr
eous cryo-s
ections, how
ev
er, is chall
enging. H
er
e, w
e focus
ed on th
e major obstacl
es to succ
ess: contamination in and around th
e microtom
e, and attachm
ent of th
e ribbon of s
ections to an
el
ectron microscopic grid support film. Th
e conv
entional m
ethod for attaching s
ections to th
e grid has involv
ed m
echanical forc
e g
en
erat
ed by a crud
e stamping or pr
essing d
evic
e, but this disrupts th
e int
egrity of vitr
eous cryo-s
ections. Furth
ermor
e, attachm
ent is poor, and parts of th
e ribbon of s
ections ar
e oft
en far from th
e support film. This r
esults in sp
ecim
en instability during imag
e acquisition and subs
equ
ent difficulty with aligning proj
ection imag
es.
Here, we have implemented a protective glove box surrounding the cryo-ultramicrotome that reduces the humidity around and within the microtome during sectioning. We also introduce a novel way to attach vitreous cryo-sections to an EM grid support film using electrostatic charging. The ribbon of vitreous cryo-sections remains in place during transfer and storage and is devoid of stamping related artefacts. We illustrate these improvements by exploring the structure of putative cellular 80S ribosomes within 50 nm, vitreous cryo-sections of Saccharomyces cerevisiae.