How long do secondary antibodies last?

When stored under optimum conditions, secondary antibodies can last anywhere from a few weeks to a couple of years. The inherent properties of the secondary antibody and the storage conditions will determine its exact shelf life. In general, secondary antibodies are relatively stable and can withstand a wide range of mild denaturing conditions. Following the manufacturer’s storage recommendations will ensure that your secondary antibodies retain their properties and remain stable for the maximum time possible.

• Keeping these storage tips in mind will help extend the shelf life of the secondary antibody:
• Aliquot undiluted antibodies prior to storage. This helps minimize exposure to repeated freeze/thaw cycles that are detrimental to the secondary antibody.
• Freeze antibodies at -20°C. At this temperature, secondary antibodies don’t experience any loss in binding capacity.
• Avoid storing secondary antibodies in a frost-free freezer. These freezers cycle between thawing and freezing to minimize buildup of frost. The repeated freeze/thaw cycles can denature the secondary antibody.
• Avoid storing secondary antibodies at very low concentrations. This can cause protein loss, compromising the stability of the antibody. Mechanically increasing antibody concentrations can also be detrimental. The best way to improve concentration and stability without any adverse effect is by adding BSA to purified antibody aliquots.

When stored properly, secondary antibodies experience minimum degradation over time, extending their use to several years.