by
experience
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:
- -20°C or -80°C
- + 4°C with preservatives like azide (0.02%) or merthiolate
- -20°C with glycerol; Final concentration of glycerol 10 or 50%
- -20°C with BSA at final concentration of 0.05-0.5%
General recommendations
- If possible, filter-sterilise antibody sample and aliquot to avoid
multiple freezing and thawing.
- Storage at protein concentration around 0.5-1 mg/ml.
- In case of IgM especially check protein stability in different storage conditions.
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:
- Thimerosal at 0,01%
- Gentamicin sulfate at 50 ug/ml
Last changed: 2009-04-02 by WebMaster