Cellulase Onozuka RS contains xylanase activity that is three time higher than Cellulase Onozuka R-10. It is often used in the isolation of plant protoplasts when combined with Macerozyme R-10 or other enzymes. It contains 2 U/mg of cellulase activity, meaning one unit of cellulase activity at pH 4.5 will liberate 1 μmol of glucose from carboxylmethyl cellulose at 40°C per minute. Cellulase activity is inhibited by glucose and cellobiose. Moreover, it is completely inhibited by Hg2+ and slightly inhibited by Mn+, Ag2+, Zn2+ and Cu2+.

Cellulase Onozuka RS is derived from Trichoderma viride. It is a multi-enzymatic system consisting of cellulase, α-amylase, hemicellulase, pectinase, and protease activity. Cellulase acts together with other enzymes to degrade cell walls by modifying celluloses, lichenin and cereal β-D-glucans. It modifies cellulose by hydrolyzing 1,4-β-D-glucosidic linkages. Other enzymes like α-amylase break down 1,4-α-D-glucosidic linkages in polysaccharides while 1,4-α-D galastosiduronic linakages in galacturans are randomly cleaved by pectinase.