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Antibody stability and additives - (May/21/2007 )

Hi Gang.

All of my reading has said that antibodies are very stable over long periods of time. I affinity purifiy my antibodies and then dialyze against 20mM NaPO4/28mM NaCl pH 7.4 and store in 0.2ml aliquots at -80.

When I want to use an aliquot I take one out of the -80 and store it at 4C until it is all used up. I typically use my antibodies for Westerns (work great) and Immunoppt (work sporadically).

Will I do any damage to my work if I add Na Azide (to 0.2%) and EDTA to 1mM to my antibody prep once I take it out of the -80?

I am thinking perhaps the erratic IP results might be a result of degradation of antibody over time.

Thanks

-pBluescript-

It would only affect your assay if you're using cells, since the azide is toxic to them. How long does it take you to go through one 200ul aliquot of antibody?

-WAstate-

Could you add azide such that the final conc. is 0.02%. This is conc. we use for some of them.

Now we are actually storing the daily aliquot in -20C ( PI Insists). Seems to be working fine.

-scolix-

QUOTE (pBluescript @ May 21 2007, 09:25 PM)
Hi Gang.

All of my reading has said that antibodies are very stable over long periods of time. I affinity purifiy my antibodies and then dialyze against 20mM NaPO4/28mM NaCl pH 7.4 and store in 0.2ml aliquots at -80.

When I want to use an aliquot I take one out of the -80 and store it at 4C until it is all used up. I typically use my antibodies for Westerns (work great) and Immunoppt (work sporadically).

Will I do any damage to my work if I add Na Azide (to 0.2%) and EDTA to 1mM to my antibody prep once I take it out of the -80?

I am thinking perhaps the erratic IP results might be a result of degradation of antibody over time.

Thanks


some Ab´s are not recommended to freeze, but adding glycerol make most freezable; use shock freezing;

we use lower NaN3 (0.001 %) but not for 2nd Ab if peroxidase labeled as NaN3 blocks peroxidase

-The Bearer-

Thanks for the replies.
I have tried storing at -20, but I thought that the regular freeze-that was adverly effecting the antibodies.
Generally I go thru 200ul in about 3 months time.

The antibodies have not been used such that they are placed on live cells.
I have thought about glycerol, but have rejected it because I don't know what effect it will have on western blots and IMP's.

-pBluescript-