The Transgenic Mouse/ES Cell Chimera Facility (TgESC) is located in the basement of the Skirball Building within the SPF Mouse Facility with available 740 sq ft space. TgESC is a resource for researchers who want to generate transgenic mice by zygote injection and mutant mice by gene targeting in ES cells to study various aspects of gene function in vivo. An ES cell culture facility and Molecular Biology lab is currently under development in the Tisch Building.

ES cell chimeras are produced by injection of ES cells into C57BL/6 blastocysts or by aggregation with outbred morulae. All ES cell lines must be MAP tested before they can be injected into the blastocysts. No exceptions can be made to this rule. It is recommended to MAP test and karyotype all newly expanded stocks before undertaking gene transfer experiments. In addition, the laboratory performs pilot injections of imported and expanded ES line to assure that line retains ability to contribute to the mouse embryo. Chimeras are provided to the research investigator at weaning for test breeding to determine germline transmission of the mutation. Aggregation chimeras between two strains of mice are also made by the facility, and by special request aggregation chimeras can be made with tetraploid morulae to produce embryos that are 100% ES cell-derived.

Additional basic services include: consultation and support in transgenic/ES cell-related techniques; supply of timed pregnant mice; training in mouse husbandry; consultation in transgenic/ES cell approaches; purification of the DNA construct; knockout ES cell lines for the production of chimeras; identification of targeting clones by genotyping.

Major equipment includes: Leica AM6000 inverted microinjection system with integrated Eppendorf NKII micromanipulator; Four Leitz DMIRB microscopes with micromanipulators; Three Eppendorf microinjectors; Sutter P-97 micropipette puller; Ten Wild dissection microscopes; de Fonbrune Microforge; Hamilton Thorne XYClone laser.