Physical responses of mouse embryos under treatments with cryoprotectants (required before rapid-freezing) and rehydration (required in the recovery processes) (Siva Tsang).
One session of services includes:
- Superovulation of donor females (if applicable)
- Harvesting embryos from up to 8 donor females
- Cryopreserving all harvested embryos by vitrification
Fee: HKD 2,000 / session (+HKD 500 per 5 years storage per strain)
Notes: Transgenic strains may have variable mating performance and productivity of embryos. No. of embryos to be cryopreserved per service can vary.
FAQ: How many embryos I need?
It depends. One may consider the following factors.
- The availability of backup supply of the strain. If a strain is not available elsewhere from a reliable reposition, and no other similar strains available, more embryos may be stocked to manage the risk of losing the strain from the planet.
- Plan to redistribute the strain. If one is prepared to redistribute the strains to collaborators or other requesters, more embryos may be stocked in advance.
- Predicted genotype distribution among the thawed embryos. In a Hetero x WT cross to produce embryos for cryopreservation, one may expect half of the embryos are hetero. One will therefore double the number of embryos when comparing with a Homo x WT strategy.
One may also consider the following practical factors.
- We put max 25 embryos in one container, thus thawing 25 embryos at a time.
- More than 95% of embryos can be recovered in vitro and half of the embryos can develop to term after surgical transfer (similar to non-cryopreserved, fresh embryos).
- Surrogates occupationally fail to maintain pregnancy, naturally, after surgical transfer of embryos.
- One may want the revived animals be males to speed up the expansion of the colony.
Please contact us for further advise.
Contacts:
Dr. Siva WH Tsang (email: tsangwh@ust.hk; tel: 3469 2418)
Miss Joy HM Pan (email: joypan@ust.hk; tel: 23585947)