Analysis of genomic DNA from Rhodococcus sp. B264-1. (A) pB264 can be observed among total genomic DNA from Rhodococcus sp. B264-1. U, undigested genomic DNA (and RNA); E, Eco RI digest of genomic DNA; H, Hind III digest of genomic DNA; B, Bam HI digest of genomic DNA; M, Bst EII digest of lambda DNA. (B) Pulsed field gel electrophoresis of DNA from Rhodococcus. L, lambda ladder (~50 kb) molecular weight marker; B, genomic DNA from Rhodococcus sp. B264-1. In addition to the chromosomal DNA, which migrates near the top of the marker DNA, two additional bands can be seen in the 250–300 kb range. Additional material migrates at less then 50 kb, although resolution of the gel in this size range is not reliable under the conditions used; S, genomic DNA from R. erythropolis SQ1. For both panels, the sizes of key molecular weight markers are indicated in kb.