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Rodent Re-Derivation Policy

1. Re-derivation of all strains from non-commercial suppliers

Starting immediately, all new mice intakes from non-commercial suppliers will have to be re-derived by embryo transfer before they can go into the tower.

2. Re-derivation of strains after sero-conversion

Starting immediately, a more vigorous elimination protocol will be followed after sero-conversion is detected for any of the following pathogens MVM, MPV, PVM, REO3, MHV, GD7, SEN, LCM, MAV, ECTR, POLY, EDIM, MYCO excluding Helicobacter. Measures include quarantine, further testing, re-derivation, or culling of any strain affected within a defined time line.

3. Cost will be defrayed collectively to all users

For mandated re-derivation as described under points 1 and 2, the $400 fee per strain for re-derivation will be paid through CLACs operating budget. PI initiated re-derivations, e.g. to get rid of Helicobacter or to introduce the strain into the barrier unit without sero-conversion, is encouraged by CLAC, but remains to be paid by the individual PI. The same applies for cryo-preserving embryos or sperm (see point 5).

4. Minimum requirements for re-derivation

Heterozygous re-derivation can be done with minimum 2 males. Homozygous re-derivation can be done with minimum one breeding pair giving raise to three female offsprings (for details see: http://gttf.uchc.edu/service%20descrpt.html )

5. Core Breeding Colony and Cryo-Preservation

In order to retain SPF status, PIs are encouraged to either expand the breeding colony and cryo-preserve the strain at a cost of $800 for 200 embryos and a yearly maintenance fee of $40 for liquid nitrogen (for details see http://gttf.uchc.edu/Service%20cryo.html ) or to maintain a small breeding colony inside the Barrier Unit (GTTF). However, the costs for those services are the responsibility of the individual PI.