Embryo cryopreservation is an essential technique for safeguarding homozygous mouse lines, ensuring their availability for future research and protecting them from risks such as infection, laboratory accidents, or other unexpected events. Moreover, freezing embryos can substantially reduce housing expenses and minimize cage usage. For non-homozygous mouse lines, however, sperm cryopreservation is generally the preferred approach.
Cryopreservation Process
- Embryo Freezing: 2-cell embryos, produced via IVF, are frozen in straws.
- Storage Quantity: A minimum of 300 healthy embryos will be cryopreserved per homozygous mouse line.
- Viability Testing: Post-freezing, a sample of embryos will be thawed and monitored for development to assess their ability to reach full term.
- Storage & Record Maintenance: The facility will store the frozen samples and maintain records at a rate of $24.00 per line per year.
Embryo Generation
- Embryos will be created through IVF using frozen or fresh sperm.
- Multiple attempts may be required to obtain enough embryos for storage.
Service Request Checklist
- Submit a Service Request
- Transfer Male Mice
- Provide 1-2 males (2-6 months old, proven breeders, if possible).
- Confirm genotyping before transfer.
- Transfer males through ULAR using the form
- The males must be tested for pinworms and the results sent to ULAR-DX@lists.upenn.edu before ULAR will approve the transfer.
- Transfer Female Mice
- Provide 5-10 females (3-4 weeks old).
- Females must be transferred on the Thursday before the scheduled service date using the same transfer link as above.
- If the females are not weaned, pinworm test the mother and transfer the entire cage.
- Investigators should contact Kathleen Moosbrugger to discuss service logistics.
Memo July 2024 regarding PSOM Subvention Requests for Mouse Cryopreservation Services
