why did precipitate formed after antibody freez/thaw ? - (Aug/01/2005 )

Precipitate formed after I thawed the affinity-purified antibody from -20 degrees. But no precipitate in the antibody solution before freezing. There are so much precipitate that I think the antibody can no be used againl. What is the problem? What should I do?

hi
does your solution contains BSA? if so this protein can precipitate at cold temperatures.
Try to heat at 25° your antibody for 215' and vortex gently each 5 minutes. The precipitate should dissolve. But i would not recommend to freeze the antibody. Can't you store your stock solution at 4°?
fred

Some monoclonals and affinity purified polys will precipitate upon freeze/thawing or also upon storage at 4C. If you can store at 4C and add preservative ie azide that will probably be the best. Another buffer, pH may help.