Cutting Ribbons of Thin Sections
This is one in a series of web pages offered as an aide to electron
microscopists, with emphasis on the special requirements of
neuroscience studies. The purpose of this page is to provide a few
tips for cutting and processing long ribbons of thin sections.
The most important step is to trim the leading and trailing edges of
the block with the sharp, non-serrated left edge of a glass knife.
Approach:
- Trim the block using razor
blades that have been cleaned with acetone and alcohol to avoid razor
blade grease from getting onto the block.
- Face the block down to tissue.
- Rotate the block 90 degrees counterclockwise; angle the stage to
the left 47 degrees; and trim the trailing edge of the block until it
is smooth. I use a new knife to remove the last few microns of
tissue.
- Rotate the block 180 degrees from its present position and trim
the leading edge of the block until it is smooth.
Recommendations:
- Leading and trailing block edges should be parallel, perfectly
clean and smooth.
- To separate the ribbon of sections into grid size
lengths:
- use a pin to bounce up and down at the junction
between two sections to break them apart, or
- when a ribbon the length of one grid has been cut, turn the
thickness control of the microtome down very thin and cut a
"non-existent" section which will push the ribbon away from the knife
edge.
As with any laboratory procedure, one or another step or
recommendation may be unnecessary or easily replaced by an
alternative.
This page prepared by Ed. White who believes scientists
should not be intimidated by the prospect of thin sectioning.
Related sites:
For questions or clarifications contact Ed. White at: wisrael@ bgumail.bgu.ac.il