[Histonet] Isopropanol in processing

[Matt Ibbs]

Dear all,

I have been reading the histonet archives looking for information on 
processing through isopropanol instead of ethanol.  I've found plenty on 
the subject of using isopropanol as a means of removing xylene from the 
schedule but hardly anything on using isopropanol as a routine dehydrating 
agent.
The head of our department wishes to change our routine processing schedule 
as the price of ethanol is always rising and we have problems with taxes 
and new customs demands.  The answer would appear to be use isopropanol 
routinely and we've been trying to get a good working method but find that 
either the small biopsies are too brittle or the larger specimens (in 
particular slices through material from radical prostatectomy) are 
insufficiently processed and fall off the slides.
Presently we're thinking that isopropanol is rather more 'harsh' than 
ethanol resulting in the brittleness seen in small biopsies and so we have 
tried reducing times in alcohol in an attempt to counteract this.  Of 
course, that results in the problem of poorly processed larger 
specimens.  What is the answer?  Should we use more short steps with small 
increases in concentration (50%, 70%, 80%, 90%, 100%) before going to 
xylene or should we use longer incubation times in fewer, stronger 
dilutions (70%, 90, 100%, 100%)?
Any suggestions gratefully received.  I look forward to hearing your opinions.