[Histonet] Re: Methanol in H2O2 explanation

[Hobbs, Carl]

I thought that I answered the original Q?

Imho, 3% H2O2 in distilled water is as good as any other "recipe", given time and concentration.
Sure, use a lower conc.... IF you achieve negative rbcs.


I use water because it is cheaper.

A lower concentration will take longer....why bother??
Kill that enzyme.
If you are concerned re frozen sections....well, use Glucose oxidase system.
Far more expensive.
Good in some very messy bloody situations...


Non-reversible ( irreversible) denaturation/inactivation of endogenous Pxs is achieved by "feeding" them a massive overdose of H2O2.
This is not suicide...it's murder!
Well, depends on your definition of Life ;-)

NB: inactivation can be reversible/non-reversible so, imho, not a good term to use.
Use "irreversible inactivation"?

Them peroxidases have evolved over millions of years to survive and...we come along with hair bleach and kill them!


Re methanol/H2O2 adversely affecting Pwax sections: I say no way.
The tissue has been processed via alcohols for several Hrs.


Bottom line:
 Water/Methanol/azide/H2O2.....are your rbcs/neutrophils  colourless ??
Have you got a good section?

If yes, then your H2O2 blocking method is OK!!

So...if you use an expensive commercial H2O2 blocking reagent...why?



To be sure.....I completely subscribe to the Skool that says that if you do get some non-specific staining but, get very good specific staining....ignore the former.
Eg: if you get rbc staining with a GFAP Ab....so what?
It is only aesthetics.....

Understand what you are doing and...why.

Carl















Carl Hobbs
Histology Manager
Wolfson CARD
School of Biomedical Sciences
Kings College London
Guys Campus
SE1 1UL
Tel: 020 78486813
Fax: 020 78486816
020 78486813