Figure 5

Effect of cell density on LUC luminescence intensity. Yeast cells harboring the ADH1:LUC reporter were grown in liquid culture at 30°C for 16 h. Dilution series were prepared from the overnight culture and 20 μl of each dilution were pipetted on solid media and allowed to dry for 15 min at 22°C. The patches were treated with 2.5 mM luciferin and imaged subsequently. Average luminescence values of three replicates for each dilution were plotted against the relative cell density. Graphs with linear (A) or semi-logarithmic (B) scale are shown. Error bars represent standard deviation. The culture with 0.01 relative cell density had OD260 = 0.232 and the corresponding patches contained 8.2·10⁴ cells. Yeast cells were counted by a Burker counting chamber.