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Methodology Guidelines
Determination
of Cell Number
90
Manual de operaciones de la Cytospin 4
The macroscopic examination cannot be used as a definitive
test of the specimen. It does serve to support the eventual
diagnostic assessment, but more importantly, it provides
the information that will allow the technologist to choose
a specimen preparation protocol. A complete macroscopic
examination may include:
1 Record of specimen origin - precise anatomical site.
2 Volume of specimen.
3 Gross characteristics.
Gross characteristics describe the physical appearance of
the specimen. Important parameters are the colour of
the specimen, its viscosity, and whether the specimen is
homogeneous or contains solid tissue fragments.
The gross examination will also determine if the specimen
is fresh or if it has been fixed prior to delivery to the
laboratory. In general, it is preferable if all cytological
samples are submitted to the laboratory in the fresh state.
However, in many cases, due to transport distances or time
constraints, the specimen will be fixed prior to submission.
This must be noted during the gross examination, as fixation
may affect several of the parameters recorded during the
gross examination. Prior fixation may also constrain the
subsequent processing of the specimen. Fixation and its
effects will be discussed in a subsequent section of this paper.
Successful operation of the Cytospin requires knowledge
of the number of cells present in the sample. While the
experienced technologist will achieve reasonable results by
estimating the cell number, less than optimal preparations
sometimes result from such estimates. It is highly
recommended that all specimens be examined specifically
to determine cell numbers. Visual appearance alone is often
confusing, since specimen turbidity may be the result of cell
debris, suspended lipids, or other non-cellular materials. In
such cases, a direct determination of cell number is necessary
to ensure proper Cytospin preparations.
A78310250ES 5.1ª Edición
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