Transcription profiling by array of Escherichia coli (strain MG1655) to study cellular responses to the oxidizing effects of bleach

E. coli MG1655 was grown in MOPS minimal glucose medium at 37 degrees C with aeration to an OD600 of 0.4 - 0.5, and HOCl was added to a final concentration of 400 ?M. 0.5 ml samples were collected in liquid nitrogen immediately before, 5 min after, and 10 min after HOCl addition, and total RNA was prepared using the RNeasy? Midi kit (Qiagen). cDNA synthesis, array hybridization to Affymetrix GeneChip E. coli genome 2.0 Arrays, and imaging were performed according to Affymetrix guidelines at the Affymetrix and Microarray Core facility at the University of Michigan, Ann Arbor.

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