Abstract: Plant cells containing intra-cellular chemical compounds are induced to excrete the compounds by maintaining the cells in a sufficiently high cell density. A sufficiently high cell density is preferably maintained by immobilizing the cells in a modified polyacrylamide gel containing polyacrylamide and a minor amount of xanthan gum or sodium alginate. Vinca plant cells can be immobilized to produce the chemical compounds, ajmalicine and serpentine. Alternative to immobilizing the cells, a sufficiently high cell density can be provided by maintaining the cells in a permeable enclosure such as a woven nylon bag.