The sole presence--without the rest of molecule forms--of G1 monomer form was sought in the homogenate of rat cerebellum with vertical slab technique with the help of polyacrylamid gel electrophoresis. As a result we got the monomer form in the case of 7 day rat, without the presence of the rest of the forms. In case of older and adult rats the rest of the forms have already evolved, so the dimer and tetramer forms are also present.