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Polyclonal antibody precipitating - (Nov/28/2013 )



I received a custom rabbit polyclonal purified antibodies (3 in total) from Thermo Fisher. When I first received them, they worked great, now there is a precipitate and the binding is decreasing for the antibody. The customer service rep told me I can try adding 0.5-1.05% BSA, but that seemed to have little effect. I have also heard of using potassium salt, but I am not familiar with this method to regain antibody activity. Can anyone give me any suggestions? Thanks. 

-Steven Cho-

I'm sorry to say that, in my experience, there is no getting the antibody to 'regain activity'.  You can try a few things to prevent any more of it from precipitating.  Has it been stored at 4C or -20C?