Possibilities of mammalian cell preservation using freeze-dried methods

In general, mammalian somatic cells are preserved in the ultra low temperature freezer or the liquid nitrogen. However, the maintenance and transportation of frozen cells are costly, and there are problems with a safety aspect on liquid nitrogen. Freeze drying, which removes moisture through sublimation, has been used for a long-term storage of food, drug, yeast. To our knowledge, little work has been devoted to freeze dry for mammalian cells. The objective of this study was to establish a FD method to preserve mammalian spermatozoa and somatic cells, and to suggest the future technology for genetic preservation.