There is a minimal difference between storing Abs at -20 or -80. The freezing of the antibody itself doesn't cause a problem, the potential problems arise through repeated freeze-thaw cycles. Freeze-thawing denatures the Ab causing it to aggregate, reducing its activity. Ideally aliquot antibodies into single-use vials so once thawed they are not frozen again.

Daniel,

Freeze thaw is a problem. With repeated change in temperature, the thermodynamic nature of the Ab and sometimes the enzymes attached (in 2ndary) may get effected. Hence, I would suggest that you aliquot for two uses (single set can run atleast 4-5 blots) and store it in higher temp (-20) and the main stock in the lower temp (-80).

Hope this solves your problem.

Best,

Somnath

The only antibodies I store at -20 are ones that come supplied in 50% glycerol, as they will stay liquid at -20, avoiding the freeze-thaw problem. Otherwise, everything goes to the -80 aliquoted and will stay good for years.

Hi Daniel 

Antibodies are stable proteins. For long periods, I always store the antibodies frozen in working aliquots. As others said repeated freezing and thawing is not recommended. Changes are minimal, but I prefer to store the antibodies at -80°C rather than -20 °C.

Antibodies are very stable in general and issues with frozen aliquots are nearly always due to freeze thawing. Therefore unless you have complete control over access to your freezer I would go for a -80 deg C. Reason? If your aliquots are small, (> 500ul) then they are bound to suffer partial thawing from -20 deg C sooner or later when people leave them out as they hunt for their own samples.