Abstract
The method of enucleating recipient oocytes by bisection with a metal-blade has been adapted to somatic cell nuclear transfer (SCNT) using zona-free mammalian oocytes, and the process named handmade cloning (HMC). Besides the simplification of enucleation without using a manipulator, this technique also provides for a reduction in the amount or the elimination of expensive equipment that is usually indispensable for conventional SCNT. In this review, we will highlight some recent studies on HMC and related studies in farm animals, especially cloning using enucleation by the gradient centrifugation of zona-free oocytes to produce a large number of recipient cytoplasts at once.
