Novel methods of membrane fusion may help women who have fertility problems due to eggs that contain defective cytoplasm. The techniques, a new method of mechanically induced membrane fusion in human oocytes and a previously described chemical fusion method, were developed by a collaboration of researchers from France, Spain, and Italy and essentially involve transferring the nucleus of a defective egg into a donor egg (Hum. Reprod., 15, 1149–1154, 2000). Most cell fusion techniques used in mammalian cloning employ electrofusion, which cannot be used for human oocytes because it activates them. In the current study, the team used a modified chemical polyethylene glycol method to essentially “glue” together two zona pellucida-free human eggs, one of which was enucleated. It also used a mechanical method performed by making a hole in the zona and then manipulating the eggs together using a micropipette. The authors say the intracytoplasmic sperm injection (ICSI) technique “will probably be the optimal way of fertilizing the reconstructed oocytes.” The technique also has potential for use in therapeutic cloning.