[Histonet] Processor question - alcoholic formalin vs. buffered formalin

[Lake, Kim S]

I attended the Tri-State Symposium in Dubuque, IA last week (which was fantastic) and sat in on a "Boot Camp for Histology" workshop.  At this workshop I realized that some problems we have been having with sectioning could be due to our processor set up.  

Before microtomy we have to soak our blocks for 10-15 minutes, and I suspect that this is because we are over dehydrating our tissues in the during processing.  Our first solution, which the cassettes sit in for about 8 hours until the overnight processing begins, is alcoholic formalin, which is 450ml buffered formalin, 900ml water, and 3300ml 95% alcohol.  Our processor is a Leica TP 1050 that has been chugging along for about 20 years now.

The reason we use alcoholic formalin instead of just normal buffered formalin has been lost to the mists of time, and I was wondering what you all use as a holding solution on your processor, and why.

Thanks!

Kim Lake
Laboratory Manager
Oral Pathology Laboratory
University of Iowa College of Dentistry
Phone (319) 384 4433
Fax (319) 353 5569