Production of chimeric mice from cryopreserved blastocysts

Mouse blastocysts derived from in vivo fertilization were cryopreserved by a simple vitrification method. Most of the cryopreserved blastocysts survived while demonstrating a normal morphology after warming (88.1%). The rate of cryopreserved blastocysts which developed to term as normal young was 56.8%, and chimeric mice were also produced from cryopreserved blastocysts injected with ES cells. As a result, 3.4% of the injected embryos developed to term as germ line chimeric mice.