Figure 2

Imaging of new Y-GECO2m. (a–c) Fluorescence images of HeLa cells expressing Y-GECO2m. For each panel, the right hand chart shows fluorescence signals for the cell enclosed with a dashed-line in response to histamine-induced Ca²⁺ oscillations. (a) Fluorescence with excitation at 480 nm. (b) Fluorescence with excitation at 440 nm. (c) Ratiometric response (excitation at 440 nm/excitation at 480 nm). (d) Fluorescent image of glial cells in dissociated rat hippocampal culture expressing Y-GECO2m. The fluorescence responses of selected regions to the spontaneous Ca²⁺ changes over time are demonstrated in the traces at the right side in the same color (excitation at 480 nm). Quantitative measurements of fluorescence responses in HeLa cells is provided in Supplementary Table 4.