This is otherwise known as formal sublimate.

Saturated aqueous mercuric chloride  9 parts
Concentrated formalin (40%)  1 part.
Keeps for years.

Some add a very small amount of acid fuchsin to colour it red as a warning.
It is extremely poisonous.

Fixation time is about 2 hours to overnight.  Remove mercury pigment.  Avoid
all metals (forceps, cassette lids etc).

For years I recycled mine.  Simply pour the used fixative into a container.
Filter and re-use.  I never noticed any deterioration in fixation at all.
It certainly beats going to all that trouble to dispose of mercuric chloride
as a hazardous waste.

Bryan Llewellyn



----- Original Message -----
From: Rena Krol <Rena.Krol@usm.edu>
To: <Histonet@Pathology.swmed.edu>
Sent: July 26, 1999 9:46 AM
Subject: formol mercuric chloride


> Hi Histonetters,
>
> One of the techs in our lab is looking for a recipe for formaol mercuric
> chloride.  We can't find it in any of our texts, either old or new.  Can
> anyone help?  Thanks!
> Rena Krol
>
>
>