Fig. 4

Efficiency of concurrent amplification of different transcripts in one sample. Two RNA samples isolated from light-induced and from dark control cells, respectively, were mixed at different ratios. Transcripts were quantified and the normalized peak area (NPA) of their specific fragments was plotted against the relative concentration of the RNA sample from the dark control cells (a) or from the light-induced cells (b). Data points of down-regulated (a), up-regulated (b), and not regulated genes fitted to straight lines, indicating that the amount of cDNA amplified by RT-PCR is proportional to the concentration of each individual transcript in the sample and independent of those transcripts the cDNAs of which are co-amplified. Correlation coefficients obtained by linear regression are displayed in each panel. Small regression coefficients indicate that there is hardly if any difference in the concentration of the respective mRNA between the two samples. The figure was prepared with R, version 3.5.2