[Histonet] Re: celloidin, collodion

[Robert Richmond]

I've never seen celloidin, collodion, or what have you - solutions of
cellulose nitrate in ethyl ether or other flammable solvents - used
for cytologic cell block preparation.

Cellulose nitrate is simply too much of a fire and explosion hazard to
allow it in a histology lab at all.

Thermo Scientific Richard-Allan Scientific - or whatever they're
called this week - offers HistoGel, a proprietary gel for cell block
preparation. I've seen it used, and at least in some labs it works
well. It's supposed to be quite expensive, in an area where the bean
counters come down hard. HistoGel requires formaldehyde fixation.

Many people used to use trypticase soy agar (TSA) purloined from the
microbiology lab, but I'm not sure they use it any more.

An old technique perhaps stiil in use is adding plasma to the cell
block pellet, and then clotting the plasma with thrombin. I don't have
any experience with it.

People have a lot of trouble preparing cell blocks.

Bob Richmond
Samurai Pathologist
Knoxville TN