Cell engineering is an important aspect of bioengineering. In general, it applies the theories and methods of cell biology and molecular biology to carry out genetic operation at the cell level and large-scale cell and tissue culture according to people's design blueprint. At present, the main technical fields involved in cell engineering include cell culture, cell fusion, cell disassembly, chromosome manipulation and gene transfer. Through cell engineering, useful biological products can be produced or valuable plants can be cultivated, and new species or strains can be produced.