Production of transgenic mice from DNA-injected embryos cryopreserved by vitrification in microdrops.

Transgenic mice were produced from DNA-injected embryos stored for 2 to 30 days in liquid nitrogen. Of the 500 zygotes collected from (C57BL/6 x CBA)F1 mice, 363 (73%) survived DNA injection into pronuclei and 246 (82%) morphologically normal 4- and 8-cell embryos were flushed from temporary recipients 48 h later. Of the 200 DNA-injected 8-cell embryos… (More)