What is Rederivation?
The procedure by which an early, pre-implantation stage embryo is isolated from the reproductive tract of a donor female and transferred to the reproductive tract of a clean recipient pseudo-pregnant female.
It is the method by which laboratory animals can be “cleaned” or decontaminated of certain pathogens before being introduced into barrier housing facilities
Will my lines require rederivation?
Yes, if they are NOT sourced from our approved vendors with high health status. Approved vendors include Charles River- Elite Health Status and Jackson Laboratory Maximum Barrier or any other supplier approved by Bioresources.
Does rederivation take more time than standard import for establishing colonies?
Yes, typically it can take up to 6 months (two breeding cycles) to expand colonies to the level required for experimental work to commence. Once embryos have been isolated, they are transferred into pseudo-pregnant recipients and the pups born can be transferred into the facility once pathogen screening results confirm their clean status. Breeding can then commence in the facility.
Rederiving imported mice:
1.Investigator to complete a rederivation request form through E-mus.
2.Provide contact details so the Import/Export Coordinator can assess health status of the incoming mice (see Import/ Export page ).
3.Provide males of the appropriate age and genotype.
4.All movement of mice into our facility must be coordinated through the Import/ Export Coordinator.
5.Females (generally wild type supplied from our facility) will be superovulated, mated to the supplied males and embryos isolated.
6.Embryos will be transferred into clean pseudopregnant recipients.
7.After litters have been weaned, one or more female parents will be sent off for pathogen screening.
8.Once a clear pathogen screening test result is received, Bioresources will return to the investigator at least one breeding pair of SPF health status. The procedure can be customized to accommodate larger numbers.
9. Once genotyping by the investigator confirms the animals have the appropriate genetic status, the original imported males will be culled.
Rederiving from frozen embryos:
- 1.Investigator to email firstname.lastname@example.org initiate request through the Import/ Export Coordinator.
2.Provide details such as contacts, address and health report so the Import/Export Coordinator can assess health status of the incoming embryos if they are being imported from another facility
3.Provide at least 60 embryos and details of method of freezing if they are being sent from another facility
4.All movement of embryos into our facility must be coordinated through the Import/Export Coordinator.
5.Embryos will be thawed and transferred into clean pseudopregnant recipients
6.After litters have been weaned, one or more female parents will be sent off for pathogen screening.
7.Once a clear pathogen screening test result is received, Bioresources will return to the investigator approximately 25% of the embryos as pups of SPF health status depending on the line and success of the embryos transfers.
8. The animals can then be genotyped.
Bioresources cannot guarantee success though experience indicates rederivation is mostly successful as long as the animals used for import are fecund and embryo transfer is successful.
For Imported lines (live mice):
The procedure typically takes around 12 weeks though can be as short as 8 weeks.
For frozen lines (embryo):
The procedure typically takes around 9 weeks though can be as short as 8 weeks.
For further information, please contact email@example.com