[Histonet] question regarding pH in retrieval solutions

[Gudrun Lang]

Hi all!

Although I am rather long in the business, I came across a question, that I
wanted to share with you.

With IHC-HIER one uses high-pH tris-buffers at about pH 8-9 and low-pH
citrate-buffers at pH 6.

Tris-buffers are sensible to changes in temperature – the higher the
temperature, the lower the pH.

 

A tris-buffer of pH 8,5 at roomtemperatur should have about pH 6,5 at 98°C
(if my KI-friend calculates correctly).

The citrate-buffer is not affected by temperature.

 

So as a result the actual pH in the retrieval-solution would be rather the
same. That makes me thinking...

Where is the difference? Why do high-pH buffer work mostly better? Am I
totally wrong with my assumptions?

 

I would be happy about any input.

kind regards

Gudrun Lang

 

Gudrun Lang

Biomedizinische Analytikerin

Austria