FIG. 2.

Fluorimetric detection of ethidium efflux from BD170-VB B. subtilis cells overexpressing different variants of FLAG-modified Bmr. Cells loaded with ethidium bromide in the presence of reserpine were placed into drug-free medium, and their fluorescence (λ_ex = 530 nm; λ_em = 600 nm) was monitored as described previously (4). Fluorescence is proportional to the amount of ethidium remaining in the cells. wt, wild type.