Restriction digests of the clone give the following sizes (kb): PstI--4.6; EcoRI--2.3, 1.7, 0.7; ClaI--4.6. Since the cassette omega-hyg and the plasmid pHP45 have almost identical size, it is convenient to cut the pHP45omega-hyg with BamHI releasing the omega-hyg cassette and with another enzyme such as PstI that cuts pHP45 but not the cassette in order to obtain a DNA fragment containing the cassette alone. One of three vectors (ATCC 87626 - 87628) containing antibiotic resistance gene cassettes, derived from the omega interposon. The cassettes can be used for insertional mutagenesis or for vector construction. In E. coli, expression without selection is required before plating on selective medium. Antibiotic concentration used for selection on standard media, e.g. Nutrient Agar for E. coli and R2YE for Streptomyces lividans is 200 ug/ml hygromycin (Hm). |
