text: Cell walls are made of a variety of polysaccharides.  Protoplasts can be made by degrading cell walls with a mixture of the appropriate polysaccharide-degrading enzymes:
  During and subsequent to digestion of the cell wall, the protoplast becomes very sensitive to osmotic stress.  This means cell wall digestion and protoplast storage must be done in an isotonic solution to prevent rupture of the plasma membrane.