We use buffered zinc formalin almost exclusively.    For those specimens we
get (mostly brain from autopsies) that are not fixed in Z-Fix (Anatech), we
wash them at least an hour in running tap water.
This seems to reduce and prevent the salts that precipitate when zinc
formalin and regular 10% formalin are mixed together.   Another step we use
is the first alcohol on our processor after the Z-Fix is 50% alcohol or
less.    This also prevents precipitation forming.    Hope this is helpful.
Hazel

> -----Original Message-----
> From:	Jennifer MacDonald [SMTP:jmacdona@mtsac.edu]
> Sent:	Friday, June 01, 2001 1:16 PM
> To:	Terry.Marshall@rgh-tr.trent.nhs.uk; histonet@pathology.swmed.edu
> Subject:	Re: RE:zinc
> 
> The Journal of Histotechnology/Vol.17, No2/June 1994 had an article by a
> group at Texoma Pathology Foundation (Frieda Carson et al) regarding using
> Zinc Isopropyl alcoholic unbuffered formalin as a post fixative.  We did
> parallel studies with their procedure and were extremely pleased.  The
> hospital has been using it ever since.  We had no problems with
> precipitates
> or pigment.
> 
> Jennifer MacDonald
> 
> 
> 
> From: <Terry.Marshall@rgh-tr.trent.nhs.uk>
> To: <histonet@pathology.swmed.edu>
> Sent: Friday, June 01, 2001 7:50 AM
> Subject: RE:zinc
> 
> 
> > I sent this a couple of weeks ago but suspect, from the lack of replies,
> I
> misaddressed it.
> >
> >
> > This is particularly addressed to John K., who tells us:
> >
> > "You should not move a piece of tissue from a phosphate-buffered
> formaldehyde
> > fixative into a zinc-formalin, because the zinc ions will make
> > insoluble zinc phosphate as soon as they bump into phosphate ions
> > derived from the perfused liquid."
> >
> >
> > For those of us that love zinc fixation, but don't have it available
> other
> than as a post-fixative for a few hours post cut-up when it is our turn on
> surgicals, what are us poor boys to do?
> > I know the problem and try to minimise it with a wash beforehand, but
> realise that this is less than satisfactory.
> > What is the way to go in these circumstances?
> > Is an alcoholic zinc a better option?
> > If so, what (non-commercial) formulation?
> >
> > Terry L Marshall
> > Histopathologist
> > Rotherham General Hospital, Yorkshire
> >
> >
>