See Britton RA et al. J Bacteriol. 2006 for protocol details.
Data processing
Cy3 and Cy5 signals for each spot were normalized to the total Cy3 and Cy5 signals of the array. The total signal for each channel was calculated by summing the values of the total signals for each spot, which was calculated by multiplying the mean signal intensity (per pixel) by the number of pixels. Ratios were calculated only when the spot had a signal 1 standard deviation above background for 50% of pixels in each channel.