Self-purified antibody - viability and quantity problem - (Sep/14/2005 )

hello!
I purified antibodies by affinity chromatography and my problem is that the amount in fine is not that great and after some time stored at 4°C or even -20°C it is not working that well in blot (I have to increase the concentration) even though it's working fine in IF!

all suggestions, commentaries, help, withcraft will be welcomed!!

I, too, found decreasing activities of antibodies when stored at 4 or -20°C for some time. one possibility is to add some sodium azide to conserve the AB, or, the method better suited for me, store small (1-5 usage doses) aliquots at -80°C, thaw only once and use up the antibody quickly...

mike