RE: wierd artifact on tissue
can test for the presence of incompletely removed paraffin by examining
"deparaffinized" unstained sections between crossed polarizing filters (i.e.,
one below the microscope stage [e.g., on top of the blue filter] and the other
one above the specimen [e.g., sitting on top of the wet coverslipped
section]). Rotate one filter only until the field-of-view becomes
dark. Any residual paraffin will rotate the polarized light and appear
white, since the paraffin is allowing light to be transmitted through those
areas of the sections. To fully appreciate the effect, first use a section
that has not been through xylene.
Historically, some authors have pointed out that there is always some
residual paraffin, but not enough to be problematical in routine
applications. Wiith the advent of image analysis techniques many years
ago, which are sensitive to residual paraffin, complete deparaffinization can be
accomplished by dewaxing the sections twice (i.e., immerse in xylene per
routine, rinse in alcohol down to water, back up to alcohol, and then through a
second set of xylene baths).
Synthetic waxes also rotate polarized light.
experienced a similar problem and it was identified by a pathologist as
inadequate removal of wax during the staining process. This can be caused by
the xylene not dissolving out the wax properly. Check the times on your
staining machine. Alternatively the machine is not being changed often
Hello all. I could really use some help. Today, the
pathologist called to say that she is seeing an artifact on the tissue. It
looks like clusters of fine PCP organisms, only that they are not. Like
someone took a very fine tip black marker and made circles around the cells.
She said it is not on every slide. The slides she had me check were prostate
needle bx's and an antrum bx. The only change in our routine has been that we
are demonstrating a recycling system for alcohol and Xylene. I have not used
the recycled product on the tissue processor or the H&E autostainer, but I
have placed the recycled Xylene in our glass Coverslipper.
appreciate any and all comments.
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