The transcriptomic response of E. coli to triclosan exposure

The gene expression profile of E. coli K-12 MG1655 grown in minimal medium treated with 0.12 mg/L of the biocide triclosan has been analysed using whole genome oligonucleotide microarrays. "Control" RNA was isolated from three independently grown 50ml MOPS minimal media cultures of E. coli K-12 MG1655. “Test” RNA was isolated from three independently grown 50ml MOPS minimal cultures of E. coli K-12 MG1655, to which was added 0.12 mg/L of triclosan after reaching mid-logarithmic growth phase (OD600 ~ 0.7 +/- 0.02). Keywords: dose response Cy5-labelled cDNA probes were synthesised from three independent biological extractions of RNA from E. coli MG1655 unexposed to triclosan. Cy3-labelled cDNA probes were synthesised from three independent biological extractions of RNA from E. coli MG1655 exposed to 0.12 mg/L of triclosan. A dye-swap control was also included, whereupon the control cDNA probes were labelled with Cy3 and the test cDNA probes labelled with Cy5. Probes were mixed to allow comparison of the control and test expression profiles and hybridised onto an E. coli spotted oligonucleotide array.