Dear  Katrina,

> So I made a mistake in making up our 10% neutral buffered formalin.  I did
> everything else right, except that I added Potassium Phosphate, dibasic,
> instead of Sodium phosphate dibasic.  I made up a lot of this and dont want
> to waste it.  What deleterious effect will this cause.  Will the tissue
> still fix properly?
> 
Take a measured sample, check the pH. Add appropriate NaOH or HCl to 
pH to 7+/- 0.2. From this, extrapolate for the total volume of 
fixative. The effect should be the same as properly made buffered 
formalin but be careful of how much acid/alcohol you add, you might 
inadvertantly dilute the formalin too much.

Regards, Tony
 
Tony Henwood
Senior Scientist
Anatomical Pathology
Royal Prince Alfred Hospital
Sydney, AUSTRALIA

http://www2.one.net.au/~henwood
http://www.pathsearch.com/homepages/TonyHenwood/default.html