Protoplasts are spherical bare plant cells produced by the elimination of the cell wall by means of digestive enzymes; plant protoplasts can be grown in defined environments and will form a new cell wall, divide and, in many cases, regenerate whole plants. Protoplasts are a unique experimental system for studying the structure and function of plant cells.

The enzymatic method is a technique widely used for the isolation of protoplasts. The advantages of the enzymatic method include good yield of viable cells and minimal or no damage to protoplasts. Protoplasts can be isolated from a wide variety of tissues and organs, including leaves, roots, shoot apexes, fruits, embryos and microspores.

R-10 macerozyme, also known as pectinase, is an enzyme isolated from Rhizopus sp. This enzyme is used for the isolation of plant cells because it has a high pectinase and hemicellulase activity. R-10 macerozyme is often used in combination with Onozuka R-10 cellulase for protoplast isolation.