Rederivation

Rederivation is a service of converting valuable transgenic lines into Specific Pathogen Free (SPF) status.

The embryos from animals, which are carrying or suspected of carrying pathogenic agents are removed and transferred into pathogen free animals. The embryo transfer method is the only one, which guarantees the removal of adventitious agents (viral, bacterial and parasite contamination) from your colony giving you pathogen free animals to work with.

We offer 2 options to rederive the line:

Option 1 - Heterozygotes rederivation (standard procedure) - Investivagor provides 3-5 transgenic males (2-6 month old, sexually mature and preferable previously successfully bred males). The Facility provides 5-20 donor females (6-8 weeks old) (C57Bl6/J, FVB, Wistar).

Option 2 - Homozygotes rederivation (recommendated for specific genetic background) - Investivagor provides 3-5 transgenic males as described above and ~10-20 donor females (6-8 weeks old).

After hormone-induced superovulation and mating, embryos are collected and transferred into foster mothers (mice CD1, rats SD). The tissue fragment from offspring will be collected for genotyping.

Clients must supply the following:

• Completed rederivation protocol (Embryo Transfer.pdf )

• Animals: at least 3 males of the strain to be rederived for standard procedure and  both males and donor females for homozygote rederivation (or specific genetic background)

• For rederivation from the frozen embryos the Investigator provides at least 100 frozen embryos (Line Reconstitution from Cropreserved Embryos.pdf)

Special notes

The standard price of the embryo transfer service includes up to 3 attempts of the line rederivation.  

If the provided males fail to mate after 2 attempts or there will be no fertilized embryos, the investigator will be notified.

If the foster females fail to deliver live pups, the process will be repeated at no additional cost (other than the cost of more female egg donors, if needed). The investigator must inform the facility if the strain exhibits any development problems, severe defects or lethality, so that the pups can be properly monitored.

If the foster females fail to deliver pups of the proper genotype, the process will be repeated at no additional cost (other than the cost of more female egg donors, if needed) AFTER the investigator has done appropriate genetic testing on the 'dirty' animals to confirm their genotype.

If the investigator has not contacted the facility with the results of the genotype by weaning, all the pups will be transferred to the investigator's protocol number and account.

If the rederivation fails, the process will be repeated at no additional cost.

Submission form can be sent together with animals, as well as scanned and e-mailed in advance.

Do not hesitate to contact us for any questions:

j.przybys@nencki.edu.pl

a.klejman@nencki.edu.pl