The correlations between the number of HEK293T cells (black lines) or E. coli colony forming units (CFUs, red lines) and (A) relative activity units (RLUs) and (B) the corresponding moles of ATP. The RLUs were determined from bioluminescence assays using the PLG2 assay mix, as described in the Materials and methods and standard curves (similar to Fig. 2) were used to calculate the corresponding moles of ATP. Assays were performed in triplicate. Symbols represent mean values, and lines represent the linear data fit. Error bars indicate the standard deviations among replicates. Pearson’s correlation coefficient (r) and the associated significance (p) values were: r=0.999, p<0.001 for the number of HEK293T cells vs. RLUs or moles of ATP; r=0.999, p<0.001 for the number of E. coli CFUs vs. RLUs or moles of ATP.