Genetically Engineered Mouse Model Services

A Full Suite of GEMM Services

Our genetically engineered mouse model, or GEMM, program offers state-of-the-art services for the development and maintenance of transgenic mouse strains, including all modern genome editing tools and expertise in mouse transgenesis. We use CRISPR/Cas9 gene editing, which offers several advantages over traditional mouse transgenic technologies, including time savings, cost effectiveness and a potential reduction in animal usage. We continue to pursue new technologies and develop novel resources for preclinical research.

Our expert staff work with investigators from the first stages of experimental design through successful project completion.

Schedule With Us

To schedule services with the Preclinical Modeling Core Lab, or to get more information about how we can work with you, contact the GEMM program lead:

Dr. Priti Singh
GEMM Scientist

Preimplantation mouse embryo development from pronuclear to blastocyst stages. Images (from left to right) represents pronuclear, cleavage  (2-cell and 4-cell stage) and blastocyst stages, respectively.
Preimplantation mouse embryo development from pronuclear to blastocyst stages. Images (from left to right) represent pronuclear, cleavage (two-cell and four-cell) and blastocyst stages, respectively. Images by Areum Yoon and Dr. Priti Singh

Current Services List

CRISPR-mediated gene targeting in mice

We provide a four-phase CRISPR/Cas9 genome-editing service that allows researchers to acquire desired alleles (null, conditional, precisely mutated reporter or tagged alleles) in mice. 

Phase I: Planning and preparation (2-3 weeks)

  • The principal investigator and GEMM team hold planning session(s).
  • The PI approves the experimental strategy.
  • GEMM staff obtain all materials required for CRISPR/Cas9-mediated mouse transgenesis (gRNAs, Cas9, donor and recipient mice).

Phase 2: Gene editing and embryo transfer (1 week)

  • Our team delivers purified gRNAs and Cas9 into >150 one-cell embryos from the C57BL/6J strain background or an alternative background as the project necessitates.
  • Our team transfers two-cell-stage embryos to pseudo-pregnant recipient mice the following day (~25 embryos per recipient).

Phase 3: Tissue collection and genotyping (4 weeks)

  • Following successful birth, we provide tissues of resulting pups to investigators for genotyping. We can provide genotyping in-house for an additional fee.
  • We will house F0 animals until the wean date; afterwards, animals we house accrue additional costs.

Phase 4: Mouse selection (2 weeks)

  • We will ship or transfer the user’s selected mice to the appropriate facility.
Mouse Transgenesis Workflow
Image by Dr. Priti Singh

Mouse sperm cryopreservation

We offer sperm cryopreservation services for effective mouse colony management. We collect and cryopreserve 75-100uL of sperm in each of 21 straws with cryopreservation media at two different cassettes in our tightly controlled facility. We will validate successful cryopreservation by motility analysis at no additional cost. Sperm motility does not guarantee viability. We also offer post-cryo quality assessment within 24 hours by in vitro fertilization of oocytes and progression to two-cell stage embryos.

Users must provide two healthy adult males as sperm donors (age 10-16 weeks, preferably with established breeding history). Cryopreservation success depends on the strain, transgenic mutations, age, breeding history and health of the donor male. Strains on common inbred backgrounds are most successful. Mice rederived from cryopreserved sperm will be heterozygous and/or wildtype.

Sperm resuscitation/rederivation

We carry out in vitro fertilization of oocytes using cryopreserved or fresh sperm followed by embryo transfer surgery into the foster mother. We guarantee production of pathogen-free animals.

Included: Experimental consultation, donor and recipient females, all materials for IVF, superovulation of donor females, collection and transplantation of embryos into recipient females, ear/tail tissue collection and animal housing until weaning.

The adventitious pathogen status of a transgenic mouse line may impact breeding efficiency, health and life span and experimental variables such as immune response or microbiota. Adventitious agents are critical research confounders. We perform mouse strain rederivation to eliminate adventitious agents when they are identified during quarantine or routine murine health surveillance or as requested by researchers. 

Embryo resuscitation/rederivation

We thaw cryopreserved embryos and transfer them into pseudo-pregnant recipients via oviduct- or uterus-transfer surgeries.

Included: Experimental consultation, recipient females, collection and transplantation of resuscitated embryos into recipient females, ear/tail tissue collection and animal housing until weaning.

One-cell embryo microinjection/electroporation

For those investigators who want to partially prepare their materials (plasmid, gRNA, etc.), the GEMM program also offers one-cell embryo pronuclear microinjections onto the desired strain background. We will ask clients to provide quality control data for all pre-produced materials. We only use C67Bl/6J embryos for pronuclear injection; however, we will alter the strain background based on client request.  

Speed expansion

We can help with the rapid expansion of an age-matched mouse colony via technically challenging IVF and embryo-transfer surgeries. 

Embryo cryopreservation

We can cryopreserve embryos from strains with unique genetic backgrounds or multiple genetic mutations requiring homozygosous frozen materials. We will work to meet all clients' needs.  

Planned Future Services

Blastocyst microinjections

Questions about our GEMM services or how to schedule with us?