Rederivatization Services

The Transgenic Core Facility at the Penn State College of Medicine provides a centralized facility for the production for the rederivation of mice. Specific-pathogen-free housing is the current standard for experiments involving genetically altered mice. The PSU College of Medicine is in transition toward this standard. We have a barrier wing for rodents in the animal facility and several investigators have purchased ventilated micro-isolator units to further protect specific-pathogen-free animals. However, there are still many investigators that have mouse lines housed within a part of the facility that has several undesired pathogens, as well as investigators desiring to import mice from facilities harboring pathogens. Infections with pathogens have the potential to significantly alter experimental outcomes and make it virtually impossible to collaborate with researchers with “clean colonies” inside and outside of this institution.

The Transgenic Core Facility performs embryo transfer in mice to generate specific-pathogen-free mice. The pups that are born from the procedure are housed in microisolator cages in ARF 144 and transferred to the investigator when serology testing is complete.

Investigator Supplies

6 males for embryo production

Males should be sexually mature (8 weeks to 6 months of age), have successfully mated before and should be housed individually 2 weeks prior to mating for rederivation. If enough embryos are not produced due to failure of males, additional costs will be incurred.

- OR -

6 pre-pubertal females (3-5 weeks of age) or 12 sexually mature females (8-20 weeks of age)

Please note:

  • Females are euthanized prior to collection of embryos and will not be returned. [Embryo production using males AND females provided by the investigator for homozygous rederivation of transgenic or knockout mice may not be as efficient, but may be desirable for maintaining certain genetic markers such as double knockouts. Additional mice/charges may be required/incurred.]
  • If the desired background strain for rederivation is known to be of lower efficiency in terms of embryo production, e.g., 129/Sv or Balb/c, additional animals may be required and/or additional charges may be incurred.

Requesting Service

The investigator must fill out and turn in an Embryo Rederivation Request Form. An approved animal protocol must be on file with the Department of Comparative Medicine before rederivation is requested and the protocol number must be provided on the Embryo Request form. It is also the investigator’s responsibility to arrange space for their mice once they have been rederived and serology testing is complete. Animal space can be arranged through Comparative Medicine by contacting Penny Devlin (x8465). The Transgenic Core will then give the investigator an estimated time frame for the initiation of the project. For more information, please see Scheduling Services.


Results 2005/2006:

Project#  # of Pups  # of Desired Genotype
1 5 3
2 8 4
3 31 19
4 15 7
5 14 10
6 11 11