Issue 3 April 2011
10
3.4
Section Cutting and Collection
Select the desired section thickness. Operate the sledge back and forth a few times to
remove any surface roughness on the specimen block caused by trimming.
Cut sections using slow. Steady forward movements of the sledge. Wax-embedded
specimens should form a ribbon of sections on the knife.
Sections can be removed either singularly or as a ribbon using forceps. Wax sections are
usually floated onto warm water to soften and flatten them. They can be collected on
microscope slides as follows:
a.
Dip a microscope slide vertically into the warm water some distance from the
sections.
b.
Carefully bring the slide close to the section so that the sections edge contacts the
slide in the appropriate position.
c.
Now raise the slide vertically from the water.
3.5
Hints on Sectioning
1.
Ensure the knife is sharp and clean. During use, the knife should be cleaned
occasionally to remove built-up wax.
2.
Wax embedded specimens usually cut more easily if they have been chilled. It is
common practice to trim a batch of wax blocks, then place them face down on a cold
plate or crushed ice to cool them. This way they can be returned to the microtome
and sections cut while they are still cold.
3.
A slow, steady cutting action is needed to obtain the best results. However, different
specimens may benefit from different cutting speeds, so experimentation will
sometimes bring improved results.
4.
If the section ribbon is excessively folded, creased or compressed on the knife, first,
float it onto cold water and flatten it with the aid of a small artists brush. Now collect
sections with a microscope slide and carefully re-float onto warm water.
5.
After collection, dry the wax sections onto the slides using either an oven or a
hotplate. Using temperatures 10º - 20º above the melting point of the wax, sections
will flatten and stick to the slide without being damaged.
For more detailed instructions on the preparation, cutting and subsequent staining of paraffin
wax sections, see any conventional text book of histological technique.
