How to store antibodies? General considerations


Antibodies present in serum
This is a very stable format for antibody storage. In -20°C or -70°C serum can be usually stored for years. In some specific cases this time can be shorter for anti-peptide antibodies. For very short time periods serum can be stored at + 4°C. In some cases more careful freezing with a first step at -20°C followed by -70°C can be beneficial.


Total IgG fraction
Generally antibodies in this format are stable. They can be stored in -20°C or -70°C for years. For short-term use some azide to the final concentration of 0.02 % can be added or other preservative.

Total IgY fraction
Purified IgY fraction is very stable. Even at room temperature (although we do not recommend it as storage conditions). IgY can be stored at + 4°C with 0.02 % sodium azide (note: azide inhibits activity HRP enzyme) or gentamicin sulfate (50 ug/ml).
Avoid freezing and thawing of IgY or storing it on dry ice.

"The IgY preparations were stable over time. No loss of antigen recognition was observed after storage for 3 years at + 4°C. F.De Ceunick et al. Journal of Immunological Methods 252 (2001) 153-161.



Affinity purified antibodies
Are the most fragile. Care should be taken when considering storing conditions, which should be checked experimentally for every single antibody. Affinity purified antibodies against different epitopes can vary in stability. Some will precipitate directly after the purification, while the activity may still remain. It is difficult to predict storage conditions for a given antibody in advance - there are some alternatives to be tested:
Suggested storage conditions - to be tested:


General recommendations

Important note: Sodium azide will inhibit horseradish peroxidase as well as interfere with some coupling methods and biological assays. However, the amount present in IgY preparation (0,02 %) can be washed away in ELISA or Western Blot when IgY is used as primary antibody at dilution at least 1:2000.
Alternative agents for preventing bactrial growth in antibody solution: