Fig 3.

(a) Fluorescence of SOS reporter strains as a function of time after UV irradiation. (b) SOS Promoter activity, rate of GFP production per OD unit. E. coli strain AB1157 with SOS reporter plasmids was grown in 96-well plates at 37°C in a multiwell fluorimeter; a UV dose of 5 Jm⁻² was given at midexponential growth (t = 0). (c) Unsmoothed GFP fluorescence (background subtracted) for repeat experiments performed on different days. Each point represents one time point, for a total of 99 time points per operon for eight operons. A perfect repeat would be on the x = y diagonal; also shown are parallel diagonal lines representing 10% errors. The mean error is 10.4%. UV = 5 Jm⁻².