Restriction digests of the clone give the following sizes (kb): EcoRI--3.9, 2.6, 1.6; HindIII--5.4, 2.6; SalI--8.1. Because resistance levels may vary, it is important to determine the proper antibiotic concentration for each strain or isolate. One of a series (ATCC 37653 through 37657) of vectors for in vitro mutagenesis (via the omega interposon) of gram-negative bacteria. pHP45:omega was cut with BssHII + SphI (removing the spcR/strR gene) and the ends were made blunt. This was ligated to a blunt-ended 4 kb SmaI/BglII fragment of pME495 containing the mercury resistance operon of Tn501. |