Δ-vs-Σ plot of the PM- and MM-isotherms shown in Figure 1 (part a, see Eq. (9)). The parameters α and β now specify the height and width of the Δ-vs-Σ trajectory of the PM/MM-probe pair. Part b shows the fraction of specific transcripts bound to PM- and MM-probes (xSP, P = PM, MM; and their log-mean, <...>) and the total fraction of occupied probe-oligomers (ΘP, and of their mean). Note that the fraction of specific transcripts steeply increases in the mix-range whereas the occupancy mainly increases in the sat-range (see Eqs. (17) and (16), respectively).