Restriction digests of the clone give the following sizes (kb): EcoRI--7.7, 0.3; BamHI--8.0; HindIII--8.0; PstI--3.5, 3.4, 0.9; SalI--4.6, 3.4. Do not incubate with carbon dioxide when using ribostamycin. The TSTE element is a 2.2 kb BamHI fragment that includes neoR from Tn5 flanked by Haemophilus-specific uptake sequences. Ribostamycin resistance is useful to select for the presence of neoR in both E. coli (40 ug/ml) and H. influenzae (15 ug/ml). Copy number is estimated at 6-13 per cell in both H. influenzae and E. coli. J.M. Musser |