Tips and hints for the storage of antibodies

Storage of lyophilized antibodies

All our products are shipped lyophilized (freeze-dried). Unlabeled antibodies are stable without loss of quality at ambient temperatures for several weeks or even a few months. They can be stored at 4°C for several years.
Fluorescence-labeled antibodies should be reconstituted immediately upon delivery.

After reconstitution by addition of water storage conditions depend on the type of antibody:

Monoclonal antibodies

Ascites. When ascites is reconstituted, we usually add small amounts of azide or thimerosal to prevent microbial growth. Ascites should be stored frozen. Monoclonals usually do not suffer from repetitive freeze-thawing but you may aliquot them into small samples to avoid too many freeze-thaw cycles.
Prolonged storage at 4°C is not recommended! Unlike serum, ascites may contain proteases that will ultimately degrade the antibodies. Addition of protease inhibitors helps to slow degradation.

Hybridoma supernatant should stored as ascites.

Purified IgG. Do not store diluted antibody solutions unless you add detergent or carrier proteins such as goat serum, BSA or others. IgG sticks to glass and plastic. Any IgG solution below 0.1 mg/ml protein will quickly adsorb and denature and thus loose activity! Repetitive freeze-thawing of dilute purified IgG is almost certain to lead to substantial losses.

Rabbit antisera

Antisera are more robust than monoclonals. With anti-microbials added, they may be stored at 4°C. Serum does not contain active proteases, in fact, serum itself contains a powerful cocktail of protease inhibitors. Frozen storage, however, is preferable.

Polyclonal affinity purified antibodies

Affinity purified antibodies are less robust than sera, since protease inhibitors are also removed during purification. Hence, storage at 4°C for prolonged periods (i.e. several weeks), is not recommended.