Dear Histonetters:

We've had a problem with our plastic embedded nerve biopsies on and off.
The tissue sections are stained with MAB or Toluidine blue.  Often times,
it looks like there has been poor penetration of the fixative or possibly
other solutions during processing.  Sometimes the sections are difficult to
read because there is so much artifact.  Artifacts include poor penetration
of the stain, distorted cross sections of myelinated fibers, and wrinkles.
Our EM technician has a tendency to always blame it on the fixative, so she
makes an effort to make sure the fixative is always fresh.  We've also
started slitting the perineurium with a razor blade before dropping the
specimen into fixative in hopes of improving penetration, but these methods
have not helped consistently.  I'd appreciate any recommendations all you
plastics experts might have to remedy this frustrating problem.

Thanks in advance,

Catherine Johnson
University of Minnesota Neuromuscular Lab