Genus PLC 1 article published in JoVE Developmental Biology Use of Bisection to Reduce Mitochondrial DNA in the Bovine Oocyte Laura Adams*1, Ying Liu*1, Barbara Durrant2, Elena Ruggeri2, Carly Young2, Rebecca Krisher3, Irina Polejaeva1 1Department of Animal, Dairy, and Veterinary Sciences, Utah State University, 2Reproductive Sciences, Beckman Center for Conservation Research, San Diego Zoo Wildlife Alliance, 3Genus PLC Here, we present a protocol to significantly reduce the mitochondrial DNA copy numbers in a bovine oocyte (P < 0.0001). This method utilizes centrifugation and bisection to substantially reduce oocyte mitochondria and may allow for an increased chance of development in the reconstructed interspecies somatic cell nuclear transfer embryos.