consisting of 20 mM Tris-HCl (pH 7.5) and 8 mM MgCl 2 . The fraction as CZE-37 (5ЈGmCmCmCmAmAmUmGmGmAmAmdCdCdTdG-CmAmUmCmCmAmUm3Ј), possessing a cleavage site between posi-rich in tRNA Ser was applied onto a RPC-5 column (1ϫ80 cm) and eluted with a linear gradient of NaCl from 0.4 to 1 M NaCl in a buffer tions 37 and 38 of C.zeylanoides tRNA Ser CAG. Two hundred micrograms of purified tRNA Ser CAG from C.zeylanoides was incubated at 65°C for consisting of 10 mM Tris-HCl (pH 7.5) and 10 mM Mg(OAc) 2 . As a result of these chromatographies, 300 A 260 units of purified tRNA Ser CAG 10 min with 14.4 nmol CZE-37 in a buffer consisting of 40 mM Tris-HCl (pH 7.7), 0.5 mM NaCl, 0.1 mM DTT, 0.0003% BSA and 0.4% were finally obtained.