Figure 4

Ca²⁺-imaging response characterization and grouping. (a) Pseudocolored image time series of ATP-induced Ca²⁺ response in hESC-RPE with Fluo-4 Ca²⁺-indicator from the LN + Col + 10xNid surface. The pseudocolored intensities are linearly scaled from 0 to 255. Scale bar 10 µm. (b) Schematic curve representing the parameters calculated from a single cell Ca²⁺-response: maximum relative intensity (A_max), first (T₅₀) and second (T₁₀₀) half of intensity rise time, intensity decay time from maximum to 50% (T_dec) and response duration at 50% intensity (T_dur). (c) The largest response groups with relative intensity as a function of time for each surface at 9 and 13 weeks. The parameters from (b) were used as inputs in the grouping algorithm. From each group, the strongest (magenta) and weakest (blue) responses are highlighted, in addition to the calculated median curve of the population (black). Col—collagen IV, LN—laminin, Nid—nidogen-1.