Cell fusion refers to a hybrid cell production process by a combination of membranes, cytoplasts and cytoplast in at least two cells/protoplasts under actions of spontaneous or external factors (including various physicochemical and biological factors).

Cell fusion, suitable for fundamental research on cell heredity, tumorigenesis and tissue regeneration, etc., is extensively applied in fields of microbiology, breeding and monoclonal antibody preparation, etc.. Now, it has become a crucial means of modern biotechnology.

According to ways of cell fusion, it can be divided into spontaneous fusion and induced fusion. Regarding culture of allogeneic cells, two adjacent cells are fused spontaneously, which is referred to as spontaneous fusion. As for cell fusion taking place as xenogenic cells are treated with an inducer, it refers to induced fusion.

Major cell fusion methods are described below.：
1.Sendai virus induced cell fusion: Inactivated sendai virus is used as a fusogen to fulfill cell fusion. However, such a method only has a limited application scope due to difficulty and complexity in virus preparation as well as great differences in viruses prepared in different batches.
2.PEG induced cell fusion: In the 1970s, Gao Guonan, a Chinese scientist, utilized PEG of high molecular weight as a fusogen to successfully induce fusion of plant protoplasts; on this basis, a PEG induced cell fusion method was raised by him, which rigorously facilitates technical progress in cell fusion.
3.Electronic pulse induced cell fusion: This is an efficient cell fusion approach that features high fusion efficiency, easy and convenient operation, cytotoxicity free and microscopic observation.
4. Laser induced cell fusion: Optical tweezers are utilized to capture and drag cells, so that they are exposed to adjacent cells. Locally, plasma membrane is punctured by a pulse laser beam to produce micropores and promote cytomorphosis fusion. Being accurate and reliable, such a method can be adopted to realize fusion of particular cells.
5. Ion beam induced cell fusion: An ion beam is used to process cell ultra-structures, realize cleavage of chromosome segments, remove partial chromosomes or chromosome segments; in this way, the purpose of asymmetric fusion can be achieved. Without a doubt, this is a cell fusion technique of a promising prospect.