For certain clinical questions, a limited amount of useful
information can sometimes be gained by de-paraffinising the tissue
and reprocessing for EM.
Where EM examination on tissue sent in fixative has not proved
possible, the requesting pathologist may choose to send formalin
fixed paraffin embedded (FFPE) tissue remaining from light
microscopy procedures. However, service users should be fully aware
of the limitations of examining de-paraffinised tissue
ultrastructurally before sending. This can be advised on a case by
case basis if necessary.
Again, the quality and reliability of the ultrastructural review
is dependent on the quality of initial Formalin fixation and tissue
FFPE tissue sent for EM should not be that which may have been
frozen and used for immunofluorescence procedures prior to being
fixed. Similarly, the sending of FFPE tissue which may have
originally travelled from the ward/clinic to the laboratory in
saline or similar solution is strongly discouraged.
(Last updated April 7th 2016)