Hi everyone:

I was reading through Diagnostic Immunohistochemistry by Dabbs and came across a comment that paraffin temperatures should not exceed 56 degrees when doing immuno's on the tissue later.

We have been trying to standardize our methods for optimal immuno results.  We have the occasional case where the staining is not as expected.  We are trying to eliminate as many of these problems as possible.  Is the paraffin temp really that important?  I am beginning to wonder if this is one of the reasons for those cases that should, but just don't stain positive. 

  We have been using Paraplast and Paraplast xtra for over 10 years at 60 degrees.  If I do experiment with a paraffin with a lower melting point, what can I expect?  Will my techs have a harder time cutting the blocks?  Will I need to increase my infiltration times?

Turn around time is very important, I don't want techs complaining that they can't get good routine sections just to possibly fix an immuno variable.  Also from my research so far the lower melting point paraffin is more expensive.

Basically has anybody made a change in paraffin for this reason, and was it worth it?

Ross Stapf
Histology Supervisor
Washington Adventist Hospital
Takoma Park MD