[Histonet] Re: marking small samples

[Bob Richmond]

Yves Heremans asks:

>>Does anyone know of a good method to mark (stain) small samples (tissue
or cells) prior to paraffin embedding to aid in finding back more easily
the sample in the paraffin block? Preferably something that would not
interfere with subsequent antibody staining.<<

Eosin supposedly interferes with subsequent fluorescence procedures such as
FISH.

I've seen safranin O used quite successfully for marking small specimens
while grossing. Supposedly it doesn't cause the problems eosin does. Like
eosin, it isn't visible in the stained sections.

Safranin O (C.I. 50240) - unrelated to the natural dye saffron, of course -
is used as the counterstain in the microbiologist's Gram stain, so that you
can easily get a sample of the solution from the hospital laboratory.

Supposedly alum hematoxylin can also be used for this purpose, but I've
never seen it done.

Bob Richmond
Samurai Pathologist
Maryville TN