Hi

Sodium azide is an efficient preservative, but is also an irreversible
inhibitor of peroxidase. You can use it in your buffers up to the RINSES
BEFORE the reagent that carries the peroxidase label (usually the third
stage). Thereafter, it can no longer be used. Peroxidase must NEVER come
into contact with sodium azide.

Also, check with your safety officer for the precautions when handling and
disposing of sodium azide. We prepare a 10% stock solution (keeps for
years) to avoid weighing out this toxic compound to often.

Paul

>years ago we used to add a tiny amount of sodium azide to our diluent, but
>you have to be careful as it can inhibit ihc reactions.  i will try and
>find the concentration used.
>patsy ruegg
>
>Laura Bliven wrote:
>
>> I would like to add a preservative to our Tris Buffered Saline Buffer,
>>pH 7.6, but am unsure as to what chemical and how much.  The staining
>>will be immunohistochemistries and I know some chemicals are
>>incompatible.
>> Thanks,
>> Laura

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Paul Klosen, PhD
CNRS UMR 7518 Neurobiologie des Rythmes
Universite Louis Pasteur
12 rue de l'Universite
F-67000 Strasbourg, FRANCE
tel: 03.90.24.05.01    fax: 03.90.24.05.28
===============klosen@neurochem.u-strasbg.fr==============================