Regarding Zenkers in Histo

Hello Fellow Students:

This is a message from Patricia and Josh.

In you notes and in a previous post by Pat there is mention of zenkers fluid being non-coagulating... which it is. BUT please note that after the acetic acid is added (RIGHT BEFORE USE), it lowers the pH of the potassium dichromate to 2.6. Once potassium dichromate's pH drops below 3.4, it becomes non-tolerant and coagulating.

Therefore, once Zenkers solution has been mixed with the acetic acid for use in fixation, it becomes a coagulating fixative.

Hope this makes sense... it can be hard to keep up with the brain power of Josh and Patricia ;-)

Any questions, feel free to e-mail one of them... I am brain dead!

Good luck studying folks,
Dan

Oh.. and p.s
By zenkers, I am referring to Zenkers acetic... not Helly's (zenker's formal).

Cheers,
Dan

I have notices also that the zenkers stock solution has glacial acetic acid, but when helly's is made from stock there is formalin instead and no acetic acid(in the notes). So, should the stock zenkers be just Potassium dichromate, mercuric chloride , sodium sulphate and distilled water?