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Cryopreservation and IVF

fertilization to 4-cell stage

Cryopreservation of mouse embryos, oocytes, sperm and ovaries is essential for researchers using transgenic or mutant mice because it preserves valuable mouse lines for future use without the need for long-term maintenance of breeding colonies. There are several benefits to long-term storage of mouse lines. Cryopreservation reduces the cost of animal care, saves space in the vivarium and simplifies importing and exporting mouse lines. Since frozen cells remain unaffected by mutation, genetic drift or disease, cryopreservation minimizes the risk of strain loss due to contamination, disease, breeding problems and disasters.

Since the summer of 2005, every researcher in the Gulf Coast area has become keenly aware of the potential for natural disaster, and the Tulane Transgenic Core Facility is prepared. Throughout hurricane season, we keep dry shippers ready to transport frozen embryos and sperm out of town in case of a mandatory evacuation of the City of New Orleans. The facility also maintains two dedicated freezers in order to maximize the safety of the cryopreserved mouse lines. Each cryopreservation session that is performed includes a quality control check to determine the viability of the frozen embryos. Mouse lines can be cryopreserved as embryos, sperm, and ovaries. The facility recommends freezing both embryos and sperm.

In vitro fertilization (IVF) can facilitate the recovery and expansion of mouse lines as sperm from one mouse can potentially produce hundreds of offspring using IVF. IVF is used to recover frozen sperm and be used to expand new strains brought in from other universities. This technique also has the potential to rescue valuable strains that fail to breed.

Investigators must supply the following items for Cryopreservation:

  • Completed Service Request form
  • At least 5 males, 2-4 months old for embryo cryopreservation
  • If homozygous embryo cryopreservation is essential, at least 20 female mice, 6-8 weeks old
  • 1 or 2 males, proven breeders, 3-6 months old, for sperm cryopreservation
  • Current protocol number

Investigators must supply the following items for IVF:

  • Completed Service Request form
  • At least 1 male, proven breeder,, 3-6 months old, or 2 frozen sperm samples
  • Current protocol number

General Timeline for IVF:

  • Mice arrive
  • IVF set up, eggs transferred to foster mother
  • Foster mice give birth (investigator notified)
  • Tail tips given to investigator when pups are 15-16 days old
  • Pups are weaned at 21 days old
  • The entire process normally takes 7-8 weeks

Special notes

At this time, the facility does not charge a yearly storage fee for cryopreserved embryos and sperm.

If the investigator wishes to rederive mice via IVF, additional charges may apply.

IVF with live birth and cryopreservation of embryos and can be combined for an additional charge. In addition, more females are required for this procedure.

If the foster females fail to deliver live pups, the process will be repeated at no additional cost (other than the cost of more mice, if needed).

Please send an e-mail to Ann Mullin for current pricing information. Outside investigators must be at an institution based in Louisiana.

The arrival of mice from any non-approved vendor must be coordinated with the director of the Uptown Vivarium, Amy Pierce.

Cryopreserved sperm samples should be shipped in a liquid nitrogen dry shipper, and delivery date must be coordinated with Ann Mullin.

Investigators can request that their frozen embryos be thawed and transplanted into foster mothers at any time. The facility will guarantee the recovery of at least two pups. Generally, pups will be ready for delivery within 9 weeks.

Please do not eliminate your colony until after you receive notification from the Core that your line has been successfully cryopreserved and passed quality control test thaw experiments.

 

Please contact Ann Mullin if you have questions about these procedures.

 

The Tulane Transgenic Mouse Facility wishes to acknowledge the Tulane Research Enhancement Fund for awarding funds for the purchase of equipment for IVF and cryopreservation.