I think that the idea of not heating tissue above 60 dC to maintain antigenicity was just about blown out of the water when we started using antigen retrieval methods that suggest heating the sections to 95dc for 40 min., unless there is some differences for tissue processing compared to cut sections I don't know about.  forinstance, perhaps once the tissue is processed,
embedded and sectioned it can withstand higher temps before antigens are compromised,? but i doubt it.
patsy ruegg

Ross Stapf wrote:

> 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