To increase the efficiency of cultured cells through increased cell attachment, the surface of the substrates is treated with purified fibronectm or collagen (or gelatin or poly D-lysine). This chemical is poured onto the surface of dish (substrate), excess amount drained, chemical is dried and sterilized by using UV light. In addition, the surface of substrates is also treated with monolayer of special* types of cells which is called feeder layer because it feeds the growing cells. The special cells used as feeder layer are glial cells, normal foetal intestine, mouse embryo fibroblast, etc. The feeder layer is used for the growth of neurons, epithelium of breast and coelome, and production of transgenic animals.