[Histonet] Processor dehydration cycles

[Tim Wheelock]

Hi Tom:

I deal exclusively with post-mortum brain tissue, so my situation may 
not apply to you.
I do not use formalin on my processor, since the half brain used for 
brain-cutting has already been thoroughly fixed.
So, I have the luxury of using 30%, 50%, 80%, 95%, then three 100% 
Isopropanols.
They used this protocol when I was at a different neuropathology laboratory.
I believe the rational for this was that starting with a lower 
concentration of alcohol, and then more gradually increasing the 
concentrations, would reduce the concentration gradient between the 
cells and the solution, and so avoid strong currents from harming the cells.
Also, brain tissue may be more delicate that say prostate, skin or uterus.
By the way, I actually do not know whether this "rational" is correct or 
not.
However, in general, if you can start at 70%, it can't do any harm.

Tim

Tim Wheelock
Harvard Brain Bank
McLean Hospital
Belmont, MA
(617) 855-359


Tom McNemar wrote:
 > Hello all,
 >
 > I was wondering what most people use as the first reagent after the 
formalins on their tissue processor?  We have always used a sequence of 
70%, 80%, 95%, and 100% but is anyone using 80% or even 95% to start 
their dehydration?
 >
 > Thanks in advance.
 >
 > Tom McNemar, HT(ASCP)
 > Histology Co-ordinator
 > Licking Memorial Health Systems
 > (740) 348-4163
 > (740) 348-4166
 > tmcnemar <@t> lmhealth.org<mailto:tmcnemar <@t> lmhealth.org>
 > 
www.LMHealth.org<file:///C:\Documents%20and%20Settings\TMCNEMAR\Application%20Data\Microsoft\Signatures\www.LMHealth.org>