The carboxyl terminus domain of Schizosaccharomyces pombe dicer (yDicerC) was expressed in Escherichia coli as an MBP-fusion protein (MBP-yDicerC). When the E. coli strain was cultured and induced at 25 degrees C, the MBP-yDicerC was partly expressed in the soluble fraction. It was then purified by two step affinity chromatography with amylose resin and Ni-NTA His Bind(R) resin. The purified MBP-yDicerC showed double-strand RNA digestion activity. siRNA-like products about 22-nt in length were generated.