This enucleation can be effected by simultaneous application of centrifugal force and treatment of the cell with an agent that disrupts the cytoskeleton.
Rho-zero cells are cells which have been depleted of their own mitochondrial DNA by prolonged incubation with ethidium bromide, a chemical which inhibits mitochondrial DNA replication.
The rho-zero cells do retain mitochondria and can grow in rich culture medium with certain supplements.
In 2008, the House of Lords passed the Human Fertilisation and Embryology Act 2008, which allows the creation of mixed human-animal embryos for medical purposes only.
During the two-week period, stem cells may be harvested from the cybrid, for research or medical purposes.