When storing antibodies in a -20C freezer, make sure the freezer is NOT
self defrosting design.  You do not want to freeze-dry your antibody
aliquots.  We found that a small under the counter size freezer, and
costing approximately $200 or less (Walmart, Kmart or discount store)
works well for short term storage.  It is not self defrosting.  Since most
refrigerators these days come with self defrost freezers, this was a
cheap, space saving alternative.  We store cryostat knives, xray film,
photo film and serums used frequently (fast turnover) in this freezer.

Gayle Callis