The study group in Laboratory of Molecular Biology, National Institute of Hygiene and Epidemiology, have s established a bank of natural bacteria across Vietnam (North, Central, South of Vietnam carrying restriction enzymes. The currrent bank consists of 350 natural bacterial strains showing restriction activities of 90 restriction enzymes which have previously been well-recognized and 2 new restriction enzymes. The two newly identified restriction enzymes were Sml I and BciV I isolated from Stenotrophomonas maltophilia and Bacillus circulans, recomizing multiple sequence 5'-CT(C/T)(A/G)AG-3' isolated and non-palindromic sequence 5'-GGATC-3'/5'-GTATCC-3, respectively.