I recently bought 50% Glutaraldehyde Solution from Sigma to use as a tissue fixative. The reagent should be stored at -20C. The bottle is 10ml so will last quite a while for my purposes. Is this solution ok to freeze thaw many times or should I aliquot it - say 500ul, 1ml etc? Sigma does not specify, only that it should be stored at -20c and nothing about freeze thawing. I do not know that stability of the chemical that well. Just wondering what other people do with such a solution.