Rederivation Core




   What is Rederivation?

The procedure by which an early, pre-implantation stage embryo is isolated from the reproductive tract of one mouse (donor female) and transferred to the reproductive tract of a mouse (recipient female) made pseudopregnant in order to allow implantation, gestation, and birth.   The rederivation procedure consists of collection, in vitro maturation and embryo transplantation.



      -To reduce or prevent the potential for transmission of pathogens from a mouse that is being placed in inside a barrier housing facility.

     - Embryos can either be harvested from "donor" female mice

     - Mated naturally to stud males

    - Created by assisted reproduction techniques (IVF).



For heterozygous lines:

      - Investigator will provide 5 males (8-20 weeks old)

     - Rederivation Core will purchase wild type females (up to 10) from the appropriate background (from a preferred vendor)

For homozygous lines:

     - Investigator will provide 5-10 males (3-8 weeks old)

     - 10 homozygous females (3 to 6 weeks old)

     - Females are superovulated and embryos are collected, pooled, and washed to reduce the risk of pathogen transfer.

     - The embryos are surgically transferred, using aseptic technique, into reproductive tract of pseudopregnant recipient females.

     - If other recipients are requested, the procedure falls under customized rederivation services.


Steps Involved:

  1. Rederivation request form - now through RIO.
  2. Provide documentation where the mice are coming from (defined, conventional, undefined thus indicating that additional safeguards for pathogen removal are necessary).
  3. Provide males of the appropriate age
  4. Provide the current mutant of males.
Note: Please inform core of genotyping final results and when to sacrifice the original mice.


The Rederivation Core will:

           -  Return to investigator at least one rederived litter or a minimum of one breeding pair (SPF health status).

           - Provide accurate documentation of matings upon request.

           - Rederivation core does not guarantee success.


All movement of mice must be coordinated through the LARC business office as an inter-facility transport.  Please click here for the shipping link.


Procedure rates:

      - Cost of rederivation by NM: $250

      - Cost of egg donors, recipients, and cost of per diem will be recharged to the PI's account.

      - The PI has the option to cryopreserve sperm from 2 males used for rederivation at an additional cost of $320 (Click here for Cryo Core Link).

      - If more than 5 recipients (2 rederivations) are needed, it will fall under the category of customized rederivation and extra charges may be incurred.


Time line:

Approximately 12-16 week

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