Abstract: A container system and method for cryopreservation of sperm includes first containers having walls of a desired thickness and thermal conductivity. At least one layer of thermally insulating walls of a desired thickness and thermal conductivity is disposed around the at least one row of first containers. The first containers and thermally insulating walls are capable of being immersed from a range of about 5° C. to room temperature directly into a liquid cryogenic fluid below a surface thereof and freezing the sperm, without vitrification, at a cooling rate sufficient to maintain post-thaw quality of the sperm. The cooling rate is controlled solely by the thermal conductivity of the walls of the first containers, the layer(s) of thermally insulating walls and any substance between the walls of the first containers and the at least one thermally insulating container.

Abstract: A container system and method for cryopreservation of sperm includes first containers having walls of a desired thickness and thermal conductivity. At least one layer of thermally insulating walls of a desired thickness and thermal conductivity is disposed around the at least one row of first containers. The first containers and thermally insulating walls are capable of being immersed from a range of about 5° C. to room temperature directly into a liquid cryogenic fluid below a surface thereof and freezing the sperm, without vitrification, at a cooling rate sufficient to maintain post-thaw quality of the sperm. The cooling rate is controlled solely by the thermal conductivity of the walls of the first containers, the layer(s) of thermally insulating walls and any substance between the walls of the first containers and the at least one thermally insulating container.