Level 4 of the South Cambridge facility has a dedicated transgenic unit with experienced technicians. The transgenic team provide pronuclear and blastocyst microinjection, rederivation of transgenic lines and gamete cryopreservation as optional services for users.
Pronuclear Microinjection
Where quality-assured DNA, with demonstrated transgenes, is utilised, 2-5 transgenics can be produced per standard session.
A Standard session includes:
- 20 x B6J super-ovulated females
- Injection session to replace 90-120 embryos
- 4 recipients used for embryo transfer to produce ~20 pups
- Tissue biopsy at E14
ES Cell into Blastocyst Microinjection
Using a known transmissible, quality-assured murine ES cell line (up to passage number 15), can produce litters of pups where 50% are chimaeras. The transgenics team will check the mycoplasma screen test results of the cells used to help ensure success.
A Standard session includes:
- 20 x C57BL/6J standard embryo donors used for natural pairings
- Injection sessions to replace 25-130 embryos (variable due to the number of plugs)
- 3-6 recipients used dependent on yield of blastocysts.
- ~50% of each litter born should contain chimeras of varying percentage
- Germline breeding available at additional cost
- Tissue biopsy at E14
Gamete Re-derivation
On receipt of viable fresh or frozen embryos, new strains can be re-derived. IVF can also be performed to re-derive new strains on receipt of viable sperm. DEFRA paperwork and transportation will be arranged if needed (courier charges apply) in both instances.
A standard embryo strain re-derivation includes:
- Embryo recovery (flushing or thawing )
- Oviduct/uterine transfer into pseudo-pregnant female
- Tissue biopsy at E14
- Health screening
A standard sperm strain re-derivation includes:
- Recovery using wild type super-ovulated oocyte donors of your choice. e.g C57BL/6J x 5
- IVF
- Oviduct/uterine transfer into pseudo-pregnant females
- Tissue biopsy at E14
- Health Screening
Gamete Cryopreservation (Sperm Freezing)
An IVF test is performed for each strain to gauge success of strain recovery. Optimally, males between the ages of 12-16 weeks old should be provided. Epididymis can be taken from other units instead as long as tissue is supplied and dissected as fresh as possible.
A standard strain freeze includes:
- 21 straws will be frozen down with strain 1 straw used for viability testing
- Wild Type females used for recovery test are charged additionally e.g. C57BL/6 x 2
- Once the freeze is complete, straws can be stored at the unit for an annual fee
Gamete Cryopreservation (Embryo Freezing)
An in-vitro test is performed on each strain at the start of the program to gauge how many embryos will be required to guarantee strain recovery. On average, 12 weeks of freezing is needed (when using purchased females with 6-8 young male studs performing well).
Each embryo freezing session includes:
- Inclusive 300-400 embryos frozen down and strain and viability tested.
- Extra space for 6-8 singly-housed young studs to be set up with the females (length of time held will depend on breeding rate and embryo yield per week. N.B extra space charged at your standard AMB accommodation rate)
- We can buy in female wild type mice of your choice for which there is a monthly charge. Please contact for details
- Once the freeze is complete straws can be stored at AMB for an annual fee
N.B if studs are in another unit, superovulated females can be supplied to mate so your staff can send oviducts back. Please contact the transgenic unit for details.
If you are interested in finding out more about any of these services or if you’d like to receive a quote, then please contact the Transgenics team at ubs-transgenic-services@lists.cam.ac.uk