Do all of the following at room temperature.
1.) Fix in Bouin’s (Bouin's Fixative Solution (Fischer) Cat No.: 112016) overnight in tubes.
This step should be kept short and should not include agitation. I have noticed that the intestine and liver could both benefit from shorter fixation times.
2.) Place tissue in cassettes and rinse for 2 hours in running water, then place into 70% ETOH (they may be stored here for up to several months).
There is a large jar with a lid to perform all of the following steps in.
3.) Cellosolve (Ethylene Glycol Monobutyl Ether (Fischer) Cat No.: E179-4) I – 1-2 hours, or longer.
4.) Cellosolve II – 1-2 hours, or longer.
5.) Cellosolve III – 1-2 hours, or longer.
6.) Cellosolve IV – Overnight.
7.) Toluene I – 1 hour.
8.) Toluene II – 1 hour.
9.) Paraffin I – 1 hour.
10.) Paraffin II – 1 hour.
11.) Paraffin III – 1 hour under vacuum (vacuum not necessary).