Figure 2. Buffer actions at varying [IP₃].

Representative fluorescence profiles (from different oocytes to those in Fig. 1) show superimposed Ca²⁺ transients evoked by increasing photorelease of IP₃ in the absence of exogenous buffer (upper panels) and after loading increasing concentrations of EGTA (A) or BAPTA (B). Traces correspond to different photolysis flash strengths, indicated in normalized units.