Abstract
Restriction endonucleases from Providencia stuartii (Pst 1) and Bacillus amyloliquefaciens H (Bam 1) cleave SV 40 DNA at two and one specific sites, respectively. Using EcoRI and Hind III endonuclease restriction sites as reference, the two Pst I sites were mapped at 0.050; 0.265 and the Bam I site was mapped at 0.170 of the genome length, clockwise, from the single EcoRI cleavage site.