Re: PAS Problems, more info Gayle

<< Previous Message | Next Message >>
From:Jerry Wilson <>
To:Donna Carr <>
Date:Wed, 07 Apr 1999 21:23:14 +0000
Content-Type:text/plain; charset=us-ascii; x-mac-type="54455854"; x-mac-creator="4D4F5353"

I've always been under the impression that the Schiffs should be
refrigerated, whether obtained from commercial sources or prepared in
house.  The periodic acid could be stored at room temp.  However, i learned
these techniques several years ago and maybe some things have changed.
They still work for me..might be worth a try..
good luck,

Donna Carr wrote:

> Gayle asked for more info.
>     To further elaborate on the problems we are experiencing with our
> PAS stain,  I have worked in Histology for 2 years and never had any
> problem with a PAS stain.  We also use the spit method for diastase.
> The stain has always worked beautifully.  Usually the second the slides
> are placed in the coplin jar the control turns pink.  That's why I am so
> baffled at the recent problems.  The sections are not staining enough.
> They are turning pink but not reacting like they normally do.  We stain
> liver needle biopsies and tumors with our PAS.  We used to reuse our
> reagents but have gone to using a staining rack instead of  coplin
> jars.  I did try the coplin jar method without any success.
> Our method is as follows:
>     hydrate to di H20
>     5 min periodic acid (1g/dl)
>     rinse in DI
>     15 min in Schiff's reagent
>     2 min rinse in Sodium metabisulfate solution
>     2 min rinse in Sodium metabisulfate solution
>     5 to 10 min rinse in running tap water to enhance pink
>     stain 4 min Hematoxylin
>     dehydrate, clear, cover slip
>    this is from memory and I can't remember the concentration of the
> Sodium  metabisulfate?  (0.5g/100ml)
>     1.  We used a different control, so this was the first suspected
> culprit.  We obtained new sections from autopsy liver for controls and
> ran several trials with different old control blocks and new blocks.
> Not seeing any improvement in the staining.
>     2.  We had problems with our reagents having ice crystals in them (
> we share a fridge with chemistry) and have since moved our reagents to a
> different location.  I called both companies that we get our Periodic
> acid and Schiff's reagent from and both assured me that freezing would
> NOT harm to the reagents.  Only to make sure that the Periodic acid was
> thoroughly mixed and at room temp before using.  Concerning the Schiff's
> reagent I was told that it was okay to keep at room temp and no need to
> refrigerate.
>    3. We are a small lab and keep reagents as long as possible.
> My plan of action:
> We have a new bottle of Schiff's that we are now using.  So I think the
> first thing to do is to get a section of cervix to use as a control.
> Secondly to use a new batch of periodic acid.  I don't believe we have
> the chemicals to make our periodic acid, but have a small amount used
> for our fungus stain that is the same concentration.
> Any further suggestions are welcome, sorry so long winded.  Thanks again
> for all the response.
>         Sincerely Donna

<< Previous Message | Next Message >>