Storage and Handling of Antibodies and Peptides
Antibody Storage and Handling
Since antibodies are designed to retain biological activities in vivo over periods of many weeks at body temperatures in the 41-42˚C range, they are quite thermostable.
Chicken IgY itself is quite stable under normal conditions. According to Larsson et al. (1993), “the authors have stored (IgY) preparations for ten (10) years at 4°C without any significant loss in antibody activity….chicken antibodies also retained their activity after six (6) months at room temperature or one (1) month at 37°C.” Remember that circulating IgY in chickens have half-lives on the order of months, and that the normal core temperature of a chicken is about 41°C.
Store antibodies as you would any mammalian antibody: aliquot the antibodies, and then store them in the refrigerator in the presence of anti-microbial agents. Aves Labs routinely includes 0.02% sodium azide in our custom antibody preparations, unless specifically requested not to. If you plan to use your antibodies over a period of 3-5 years, you may wish to dilute your antibodies 1:1 v/v with sterile glycerol and store them at -20°C. Storage at -80°C is only recommended when clients expect to keep their antibodies over a period longer than 5 years.
Key Do's and Don'ts
Avoid Multiple Freeze/Thaw Cycles
The biggest issue with regards to antibody stability is freezing. All antibodies are labile to one degree or another by freezing conditions, presumably due to the damage incurred during ice crystal formation. In this regard, chicken antibodies, like rabbit and mouse antibodies, will lose some biological activity (typically about 50%) upon freezing. Therefore, it is essential that multiple freeze-thaw cycles be avoided at all cost.
Keep IgY in the Dark
All antibodies (and most proteins) are also labile to light. It is essential, therefore, to keep them in the dark when storing antibodies for long periods of time.
Keep IgY in Sterile Conditions
Similarly, all proteins, including antibodies, are labile to degradative enzymes release by bacteria and other microorganisms, especially proteinases. It is essential, therefore, to keep aliquots of antibodies biologically sterile.
Storage Recommendations by Timeframe
Short-term Storage of Antibodies
For short-term (up to 1 year), we recommend storage at –4˚C in the dark. When removing aliquots, it is essential that sterile techniques be followed.
Long-term Storage of Antibodies
For longer-term storage (from 1-5 years), we recommend diluting the antibodies 1:1 with glycerol, re-filter sterilizing them, and then storing them at -20°C in the dark. Again when removing aliquots, it is essential that sterile techniques be followed.
Very Long-term Storage of Antibodies
For very long-term storage (more than 5 years), we recommend storage at –80˚C. Although there will be some loss of biological activity accompanying the freezing (typically about 50%), the remaining biological activity will be stable indefinitely.
A Note on Our Use of Sodium Azide
We routinely add sodium azide as an antimicrobial agent to all preparations of antibody in order to discourage the growth of bacteria and fungi. If you do NOT want us to add sodium azide to your preparations for any reason, please let us know ahead of time. We can substitute thimerosal or not add any antimicrobial agents at all (afterall, the antibodies will be filter-sterilized). If you want to get rid of sodium azide, we recommend simple dialysis.
Peptide Storage and Handling
Peptides should be stored lyophilized at -20°C to -70°C and kept desiccated whenever possible. Most peptides are more stable in powder form than in solution. Peptides should be warmed to room temperature in a desiccator before opening to avoid water condensation.