Christine Klein, BSMT(ASCP) at the MD Anderson Cancer Center in Houston, 
Texas inquires:

>>Has anybody heard of and/or used the new fixative called S.T.F.? I believe 
it might also go by the name Davidson's STF.<<

Well, the old fixative called S.T.F. - and it's a secret formula, and they 
can put anything they want to in it, and change it any time they want to, but 
in 1996 someone on Histonet (it was Hal Hawkins - still with us, Hal?) 
described it as:

>>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.<<

This is I think basically a fancy transport medium that results in the tissue 
fixing in alcohol on the processor.

It is quite unrelated to Davidson's fixative, which contains water, alcohol, 
formaldehyde, and acetic acid.

Bob Richmond
Samurai Pathologist
Knoxville TN