Totipotent

• Plant cells are unique; given the proper growth conditions, a whole plant can be generated from practically any cell -- the cells are totipotent. This quality makes them readily adaptable to large-scale production.
  
  

Medium

• The medium for plant cells is the same whether they are attached or in suspension. Plant cells in culture require essential elements in the form of salts, vitamins and amino acids. Because plant cells in culture lose their ability to photosynthesize, sugar must be supplied -- usually as sucrose. The medium for attached cells is mixed with agar, which makes it gel-like. The media can be made under sterile conditions in the lab or purchased commercially.
  
  

Culture

• Pieces of plant grown on agar form an undifferentiated mass called a callus. This callus can be put into suspension medium and briskly shaken, causing the cells to detach from one another. The large pieces can be screened out, and the single cells will multiply. To keep the cells healthy, they must be divided into fresh media regularly.