UCL Great Ormond Street Institute of Child Health


Great Ormond Street Institute of Child Health


Advice & planning

Our experienced team can help you advice and plan the work:

  • The aim of cryopreservation is to produce 300-400 embryos (8-cell stage)for each strain. These embryos will be distributed among 15-20 straws and stored in liquid nitrogen (20-25 embryos per straw).
  • To produce this number of frozen embryos, we need 6-8 single-housed young adult stud males, ideally 2-6 months of age. If fewer males are available, it will require more attempts to accumulate the desired number of frozen embryos.
  • Customers should be aware that rederiving or cryopreserving lines in their homozygous state will be more costly and may take significantly longer. We would advise that this is only done to preserve unique backgrounds or for lines carrying multiple mutations.
  • Rederivation aim is to produce around 50 embryos per line and transfer into 3-5 pseudo-pregnant females. This should produce enough offspring of the required genotype to start a new colony.
  • Pups will be biopsied for genotyping between 14-21 days and foster mother will be sent for screening. PCR screening results indicate clean health status; pups are released for the investigator to use. The entire process normally takes 9 weeks minimum.
  • We would strongly advice customers intending to import frozen stocks, to order at least 3 straws/vials of embryo/sperm for each line.