FIG. 3.

Accumulation of [¹⁴C]norfloxacin by E. coli AG102AX cells with either the recombinant plasmid, pBRBT201 (squares), or the vector alone (triangles). At 10 min a proton conductor, CCCP, was added to one-half of the bacterial cell suspension. Closed and open symbols, norfloxacin accumulation in cells in the absence and presence of CCCP, respectively.