Summary
Cryopreservation of a genetically modified (transgenic) mice line provides an archive where genetic drift no longer occurs and safeguards the line against elimination due to infection, disease, breeding failure or other unforeseen incidents. Cryopreservation also serves as an ethical as well as an economical choice for transgenic lines maintained solely to prevent loss of the transgenic line by freeing up animal facility space and reduce breeding costs, respectively.
NTS offers cryopreservation of both sperm and embryos. For embryo cryopreservation, please go here.
Benefits
- Protection against genetic drift or spontaneous loss of phenotype.
- Saves resources when colonies are not in use.
- Allows easy distribution to collaborators or other institutions.
- Allows for a quick rederivation into an SOPF barrier.
Requirements and time-frame
- Satisfactory health report for transfer of the animals to our facility.
- Optionally: euthanized males may be delivered (dead for <1 hour).
- 3-4 males, at least 10 weeks of age, optimally 3-5 months old, proven breeders.
- Males may be heterozygous or homozygous for the transgene.
- Sperm will be collected from ≥ 2 two males.
- Available for most strains. Cost will be higher for strains known to be difficult to superovulate, in vitro fertilize and/or implant.
- Typically completed within 1-2 weeks with standard quality control (QC).
Technical service performed by NTS
- NTS is responsible for the animal procedure permit (FOTS application).
- Planning and coordination of the project.
- Dissection and collection of sperm.
- 16-24 straws (depending on quality) will be frozen down.
- Frozen straws will be distributed into two separate liquid nitrogen tanks.
- Storage first year in 2 tanks is included.
Quality control (QC)
- Quality control (QC) - standard: test thaw followed by sperm motility check using Ceros II (sperm mobility software).
- Quality control (QC) - extended: test thaw, mobility check, followed by in vitro fertilization (IVF) where embryos are allowed to develop in culture until the morula stage.
- Quality control (QC) - full: Implantation of embryos from IVF into pseudopregnant foster mothers.
- Foster mother(s) may be culled in the days preceding birth and biopsies taken - to avoid any chance of cannibalism.
- Customer will receive biopsies. NTS expects confirmation of genotyping within a reasonable time (1 week).
Costs cover the following
- Collection of sperm from 3-4 males.
- Quality control (QC) – standard (sperm mobility test).
- If standard QC indicates low mobility, sperm form up to two additional males will be cryopreserved.
Optional service - Quality control (QC) – extended
- In vitro fertilization (IVF) and culturing of embryos until the morula stage.
- Includes cost for purchase and transport of donor females, housing, superovulation, collection of eggs, IVF and culturing of embryos.
Optional service - Quality control (QC) – full
- In vitro fertilization (IVF) and implantation into pseudo pregnant foster mother.
- Confirmed with birth of >1positive offspring from a test thaw (if customer want to confirm viable animals).
- Alternative: Foster mother(s) can be culled a few days preceding birth and biopsies taken –to avoid any chance of cannibalism.
- Includes cost for purchase and transport of donor females, housing, superovulation, collection of eggs, IVF, implantation into pseudo pregnant foster mothers, biopsies, and offspring until 6 weeks of age.
Service Fees
Estimated costs for the above service can be found on our Service Fees page.