The service aims to help the scientific community with bespoke tools to better understand the molecular mechanism of mammalian genetics and development.
The services provided may be tailored to suit each customer’s needs. The service focuses on applying a 3R approach to all of the projects undertaken.
The UCL Transgenic Service facility provides the following services:
- Morula aggregation
- Cryopreservation
- TALEN microinjection
- Rederivation/Cryorecovery
- ES derivation
- ES cell injection and targeting
- CRISPR/Cas9 microinjection and ES cell targeting
Advice and planning
Our experienced team can help you advice and plan the work:
- The aim of cryopreservation is to produce 300-400 embryos (8-cell stage)for each strain. These embryos will be distributed among 15-20 straws and stored in liquid nitrogen (20-25 embryos per straw).
- To produce this number of frozen embryos, we need 6-8 single-housed young adult stud males, ideally 2-6 months of age. If fewer males are available, it will require more attempts to accumulate the desired number of frozen embryos.
- Customers should be aware that rederiving or cryopreserving lines in their homozygous state will be more costly and may take significantly longer. We would advise that this is only done to preserve unique backgrounds or for lines carrying multiple mutations.
- Rederivation aim is to produce around 50 embryos per line and transfer into 3-5 pseudo-pregnant females. This should produce enough offspring of the required genotype to start a new colony.
- Pups will be biopsied for genotyping between 14-21 days and foster mother will be sent for screening. PCR screening results indicate clean health status; pups are released for the investigator to use. The entire process normally takes 9 weeks minimum.
- We would strongly advice customers intending to import frozen stocks, to order at least 3 straws/vials of embryo/sperm for each line.
Using the facility
The UCL Transgenic Service provides a customised knock-out and knock-in service.
We can:
- Help you design the best strategy for the targeting vector;
- Perform targeted mutations or random integrations in ES cells;
- Generate chimeras from our ES cells, or cells from other sources; for example, gene trap ES cell clones or adult stem cells.
ES cell manipulation
We will supply the ES cells and carry out the electroporation, selection and freezing of ES clones. Regretfully, we can neither generate targeting constructs nor carry out the screen of the ES cell clones for you.
Blastocyst injection and chimera production
We will inject between 100-120 blastocysts using 2-4 targeted clones and perform 8-10 transfers into recipient mice. To date, using this protocol, we have generated more than 40 mouse models. We cannot guarantee the generation of chimeric mice or germline transmission, but so far we have obtained chimeric mice in the vast majority of cases. Chimeras will be maintained by us until they are 3 weeks old and then we will send them to you at your expense.