Before human antibodies can be produced by a cow cell, the bovine immune system first has to be knocked out. Mass. The modified cells are sent to Manhattan. Ovaries are collected from slaughterhouses in Nebraska, South Dakota and Minnesota. The oocytes, or unfertilized eggs, are used to produce embryos artificially. Using a tiny glass needle controlled by joysticks, the scientists remove the nucleus from the oocyte.
Electricity is used to fuse the modified cell and the oocyte.
A chemical is used to mimic fertilization, and the oocyte is placed into an incubator where an embryo is formed. The embryo later is implanted into a cow's womb. Tara King examined oocytes under a microscope. We go through the cycle multiple times to end up with the final proper modification. On a busy day, the scientists will remove the nuclei from 300 oocytes and fuse the oocytes with modified cells.