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Methodology Guidelines
not cellular but are precipitated phosphate salts. It is often
suggested that one can dissolve these particles by acidifying
the specimen with a few drops of acetic acid. While this will
cause the salts to dissolve, acetic acid is also a classic fixative.
It will cause chromatin condensation in the cell nuclei, and
will also produce significant cell swelling. Acetic acid is a
component of Carnoy's fixative. If acetic acid is used, its
effects must be accounted for in subsequent evaluation of
the specimen.
Microbiology
Many microbiology samples are quite similar to cytological
samples. They will contain cells and the microbiologist is
interested in the association of bacteria or viruses with the
cells. The Cytospin can also be used to directly deposit
samples of bacteria onto slides. The advantages of this use is
that the deposited bacteria are generally more concentrated
than after simple smearing, and they are all located in
a defined area of the slide. Due to the small size of the
bacteria, the Cytospin is generally operated at speeds of
2000 rpm for five to ten minutes with high acceleration.
Many of the techniques used for localisation of viruses
or bacteria require the use of fixatives other than alcohol
based ones. In general, techniques using immunostaining or
nucleic acid probes will specify the use of aldehyde fixation,
such as formaldehyde (paraformaldehyde) or gluteraldehyde.
These do not affect the operation of the Cytospin, since they
are applied to the slide after the cells, bacteria, or viruses are
deposited on the slide. It is important to use a slide adhesive
or preferably coated slides for these preparations.
A78310250ES 5.1ª Edición
Manual de operaciones de la Cytospin 4
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