Antibodies are incredibly valuable tools researchers use as signal tags or markers in their experiments to tell them about the location or level of a particular protein that they are studying. Antibodies must be handled and stored with care to ensure they remain active and efficient in binding their target proteins. There is nothing worse than an antibody that does not work!
When an antibody is produced in a host animal it is in a very stable environment. In the host animal the antibody is protected by a desirable pH, temperature, and a variety of other stabilizing proteins and macromolecules that help reduce the chance of it being denatured by proteolysis or shearing and thus becoming less effective in binding the protein of interest. All this changes when an antibody is purified. Purification isolates the desired antibody from all the other proteins and macromolecules present in the serum. In doing so the overall environment of the antibody is significantly altered leading to marked effects on the antibody’s stability.
In order to limit denaturation it is important to keep purified antibodies stored in working aliquots at -20C or lower when they are not being used. Once thawed, the purified antibody’s stability is unpredictable even when kept at 4C. As a result, long-term storage (weeks or months) at 4C is not recommended. Additionally, freezing an aliquot after it has been thawed should be avoided as freeze/thaw cycles are thought to significantly increase denaturation of antibodies and consequently can greatly decrease an antibody’s effectiveness in binding the protein of interest. Aliquots from antibodies formulated with 50% glycerol in their buffer can be repeatedly taken directly from the stock vial stored at -20C without freeze/thawing due to the glycerol content.
At the end of the day, proper storage of an antibody is another critical factor researchers must take into consideration when trying to generate reproducible results in their research. Temperature can greatly influence the stability and binding effectiveness of an antibody. In order to limit temperature’s influence on a purified antibody it is essential to avoid freeze thaw cycles and to store the antibody in working aliquots. Having an Antibody That Works is indispensable when trying to generate reproducible data.
Take Home Messages:
- Antibodies must be handled and stored with care to ensure they remain active and efficient in binding their target proteins.
- Purification isolates the desired antibody from all the other proteins and macromolecules present in the serum and can markedly effect an antibody’s stability
- Purified antibodies should be stored in working aliquots (volume dependent on application) at -20C or lower when they are not being used
- Freeze/thaw cycles can greatly decrease an antibody’s effectiveness in binding the protein of interest.