[Histonet] Re: STF replacement

[RSRICHMOND <@t> aol.com]

Ten years ago on Histonet Hal Hawkins posted:

>>We have been very pleased with the results of immunostaining tissues fixed 
with Streck Tissue Fixative (Streck Labs Inc., PO 37625, Omaha, NE 68137-0625, 
(402) 691-7453). It contains Bronopol, which is 2-bromo-2-nitro-propanediol, 
and diazolidinyl urea, C7H14N4O7, with zinc sulfate and sodium citrate, and 
less than 0.1% formaldehyde. It meets government standards for disposal in 
public sewers, as not forming hazardous vapors, and for shipping as a nontoxic 
substance. Prolonged fixation does not mask antigens. I presume it is a weak 
cross-linker and denaturant. The morphology is excellent at the light level, but no 
good by EM.<<

Checking my "Funny Fixatives" file, I don't find any similar fixative. I 
think that STF may have functioned as a transport medium, so that fixation would 
occur in the processor. Ethanol would thus be the fixative unless the processor 
sequence began with formaldehyde.

A good lesson in why you should use laboratory materials of known composition 
whenever possible, rather than relying on mysterious proprietary mixtures.

Bob Richmond
Samurai Pathologist
Knoxville TN