Fig. 5. Applications: multiparameter imaging. Parallel imaging of secretion (via SRB endocytosis) and metabolism (cytosolic ATP/ADP, using Perceval) (a) and (b) or signalling (Ca²⁺, using Fluo4) (c) and (d) in the islets, with a single-cell resolution. (a) and (c): Average secretion (dSRB/dt) and ATP/ADP (a) or [Ca²⁺]_i (c) per islet. (b) and (d): Surface plots reporting the kinetics of endocytosis in individual cells (dSRB/dt) and ATP (b) or [Ca²⁺]_i (d) in the same cells within the islets. The parallel signals have been sorted according to the magnitude of the ATP/ADP (b) or [Ca²⁺]_i (d) response over a ca. 40 minute period following the stimulation with high glucose concentrations. Note that the best “PAPTers” are not the cells with the most prominent Ca²⁺ dynamics.