[Histonet] Microwave Processing

[Steven E. Slap]

Hello again HistoNetters

Yes, there are these hybrid mixtures called coagulative fixatives. 
They are usually combinations of ethyl alcohol and polyethylene 
glycol, and, occasionally, acetic acid.  They do not cross-link 
proteins.  The PEG helps prevent the shrinkage associated with the 
use of ethanol as a fixative.

The advantage of all these mixtures is that, no cross-linking having 
taken place, no subsequent antigen retrieval (or "unmasking") of the 
proteins would be necessary for IHC.  Dr. Boon has a good chapter on 
them in support of her "Boon-Fix".

To muddy the waters further, there are still other non-formalin 
fixatives, which are neither coagulative fixatives, nor cross-linking 
fixatives, based on glyoxal, such as Anatech's "Prefer", but which 
still are said to chemically "fix" the tissue.  I'll leave the 
mechanism of their chemistry to the experts.

best regards,
Steven Slap

At 3:51 PM +0100 4/21/04, Marshall Terry Dr, Consultant Histopathologist wrote:
>Kemlo asks:
>
>"Am I talking a load of..........."
>
>Inevitably:-)
>
>Kemlo,
>
>You talk as if formalin was the only fixative. What about the group 
>called, oddly enough, coagulative fixatives?
>Now .... I wonder how they work. Let me see ......
>Furthermore, you flit between the several different subjects in an 
>unstructured way.