A palette of fluorophores that are differentially accumulated by wild-type and mutant strains of : surrogate ligands for profiling bacterial membrane transporters.

Our previous work demonstrated that two commonly used fluorescent dyes that were accumulated by wild-type MG1655 were differentially transported in single-gene knockout strains, and also that they might be used as surrogates in flow cytometric transporter assays. We summarize the desirable properties of such stains, and here survey 143 candidate dyes. We eventually triage them (on the basis of signal, accumulation levels and cost) to a palette of 39 commercially available and affordable fluorophores that are accumulated significantly by wild-type cells of the 'Keio' strain BW25113, as measured flow cytometrically.

Involvement of multiple influx and efflux transporters in the accumulation of cationic fluorescent dyes by Escherichia coli.

Background: It is widely believed that most xenobiotics cross biomembranes by diffusing through the phospholipid bilayer, and that the use of protein transporters is an occasional adjunct. According to an alternative view, phospholipid bilayer transport is negligible, and several different transporters may be involved in the uptake of an individual molecular type. We recognise here that the availability of gene knockout collections allows one to assess the contributions of all potential transporters, and flow cytometry based on fluorescence provides a convenient high-throughput assay for xenobiotic uptake in individual cells.

Very rapid flow cytometric assessment of antimicrobial susceptibility during the apparent lag phase of microbial (re)growth.

Rapid changes in the number and flow cytometric behaviour of cells of E. coli taken from a stationary phase and inoculated into rich medium.Cells of E.