Mailing viable mouse freeze-dried spermatozoa on postcards

Area of Science:

• Reproductive Biology
• Cryopreservation Technology
• Genetics and Genomics

Background:

• Current freeze-drying methods for mammalian spermatozoa rely on glass ampoules, which are fragile, costly, and cumbersome for storage and transport.
• Liquid nitrogen is typically required for sperm preservation, posing logistical and safety challenges.

Purpose of the Study:

• To evaluate the feasibility of preserving and transporting freeze-dried (FD) mouse spermatozoa on thin materials.
• To assess the DNA integrity and reproductive potential of FD spermatozoa stored on plastic sheets.
• To develop a more accessible and cost-effective method for sperm preservation and distribution.

Main Methods:

• Mouse spermatozoa were freeze-dried and preserved on thin plastic sheets.
• DNA integrity of preserved spermatozoa was analyzed and compared to those stored in glass ampoules.
• Fertility was assessed by obtaining offspring after insemination with preserved spermatozoa.
• Transportability was tested by sending preserved sperm samples via postcards at room temperature.

Main Results:

• Freeze-dried mouse spermatozoa successfully preserved on thin plastic sheets maintained comparable DNA integrity to those in glass ampoules.
• Healthy offspring were produced from spermatozoa preserved at -30°C for over three months.
• Inexpensive, room-temperature transport of preserved FD sperm on postcards to another laboratory was demonstrated without special protection.

Conclusions:

• Thin plastic sheets provide a viable and cost-effective alternative to glass ampoules for preserving freeze-dried mouse spermatozoa.
• This novel method simplifies the transport and storage of genetic material, facilitating inter-laboratory collaboration and conservation efforts.
• The technique supports advancements in assisted reproductive technology and the preservation of valuable mouse genetic resources.