These ES cells may be prepared by the investigator, an external unit or our Facility.
- ES cells targeted by our Facility
The targeted ES cells are recovered and expanded from the frozen stock. Karyotypic analysis is performed to verify the genetic integrity of the clones.
Depending on the genetic background of the ES cells the host blastocysts might be C57 Bl/6 (for 129ola or 129sv cells) or C57 Bl/6 albino (for C57 Bl/6 cells).
These blastocysts derive from either freshly collected embryos or frozen stocks.
Following ES cell injection, they are transferred in pseudopregnant females and pups are born in less than 3 weeks later. If chimeras are produced, they will be delivered along with their litter mates after weaning. Breeding of the chimeras to test for germline transmission is the investigator’s responsibility, although advice can be provided by our members. Upon request the Facility can provide this service too, with additional costs.
Germline transmission of the chimeras is guaranteed at the level of a single chimera transmission minimum.
- ES cells not targeted by our Facility
When the targeted ES cells are provided by the investigator, they must be accompanied by proof that they are tested for mycoplasma. Alternatively, we can provide this service on your behalf.
The procedure we follow is the same as for the ES cells targeted by the facility. Germline transmission of the chimeras can not be guaranteed, since it is highly dependent on the quality of the ES cells provided.