How to get your Mouse Lines Cross Fostered
(e.g. to remove Helicobacter sp. or clean up an outbreak)
This service is expected to become available again in September 2009
This process is not 100%, however data on more than 500 transfers at JHU give an overall 87% rate of successful litter transfer with removal of pathogens. There is a charge of $350 for each genotype (2 litters). We will work with you if you don't get the right genotype after 2 litters.
1. Call our cross-fostering specialist, Keyata Thompson, on 2-0753 or 5-3273 BEFORE you set up mating cages
2. Meet with the specialist to discuss the procedure, collect cage labels and instruction sheets
3. Label donor cages- we will give you cards.
4. Set up matings as scheduled with our specialist. Usually we ask that matings be set up Tuesday or Wednesday to allow for transfers mid week. If you are in before 8 am the following morning, you can check for plugs for evidence of mating. After that plugs usually fall out. Assume transgenics have a gestation of 19-20 days. We will set up matings so that we have animals available for your litter so it is important that you stick to the agreed schedule. Please note: if you set up a trio, usually only one animal will get pregnant initially regardless of whether a plug is present, therefore we suggest setting up individual mating pairs (one male, one female) for this procedure.
5. Your animals should be visibly pregnant by 14 days – check at 12-14 days and call us to indicate an expected due date. This is important, particularly if your mice didn't get pregnant when you expected. It allows us to attempt to find other foster mothers for your litter if necessary.
6. Call us the morning after the pups are born. The earlier the better but always before 12.00 pm.
7. You will need to bring the pups to us and provide a fecal sample (and a blood sample if we are removing pathogens from an outbreak) from the donor mother. The pups should be in their nest in a clean cage with a barrier filter top. If your animals are housed in Ross, we can collect the pups, however you will still need to bring us a blood and fecal sample. IF YOU NEED US TO COLLECT SAMPLES FOR YOU there will be a technical services charge.
8. Note: please do not bring us the contaminated mother unless specifically requested.
9. Pup infection status is determined by testing the foster mother at weaning (4 weeks) and the pups by PCR for Helicobacter spp at 6 weeks. Results are usually available by 7 weeks. Once the pups test clean, we will arrange to transfer them to our clean facilities according to the location you have requested on the intake form.
10. Pups are strictly quarantined and you will not have access to them until we have received test results. If you need genotyping before this, please contact us to arrange for sample collection (there will be a technical services charge).
