US Patent 7601884 Method of producing cloned animals by demecolcine treatment

A cloned animal is produced by demecolcine treatment characterized by culturing the nuclear transfer embryo in vitro and transferring the embryo in vivo. This significantly improves in vitro development of somatic cell nuclear transfer embryos and maintenance of pregnancy from transfer of transfer somatic cell nuclear transfer embryos in a surrogate mother up to delivery. A nuclear transfer embryo of a non-primate mammal made by enucleating a recipient oocyte; injecting a nuclear donor cell into the enucleated oocyte; fusing together the injected enucleated oocyte with the injected nuclear donor cell to form a fused oocyte; activating the fused oocyte; and treating the activated oocyte with demecolcine to form the nuclear transfer embryo.