Hello,

>For staining sections I know that it takes longer to stain thin sections 
than 
>thick sections. 

It would help to know which procedure(s) you are questioning.

I believe that although thin sections are more easily stained, the applied 
stain is also more easily washed off in subsequent rinses whether they be 
water, 95% alcohol or whatever your procedure requires to differentiate.  By 
staining longer, you are probably just giving yourself more to wash off in 
order to come up with the same stain intensity. 

John mentioned the permeation of thick versus thin.  I agree.  As an example, 
use a felt tip pen on tissue paper versus construction paper.  Same 
difference.  Now try rinsing it out.  Readily out of the tissue paper.  Takes 
a while with the construction paper.  If your protocols are written for thick 
sections, the stain in thin sections will be washed out in the rinses.  
Therefore to achieve the correct staining intensity you would have to 
increase the staining times to compensate for your rinses.  Make sense?

Pam mentioned that with thin sections you have less to look at.  Does the 
pathologist realize this?

>What I would like to know is it the same for oxidation of sections with 
periodic >acid?

Periodic acid oxidation applied to thin sections should not change as 
periodic acid carries oxidation to the aldehyde stage and stops.

Permanganate and chromic acid, on the other hand, carry oxidation past the 
aldehyde stage so that with thinner sections you may wish to shorten exposure 
time.  

Once again, it would help to know to which procedure(s) you are referring.

That's my two cents.

Matt Bowers
Lab Manager
VPMG
Visalia, CA