Figure 1.

Effect of extracellular divalent cations on the fluorescence of CHO cells loaded with Calbryte (A) or Fluo-8 (B,C) dyes. The time-lapse imaging began in a physiological solution with 2 mM Ca²⁺ (considered as a baseline, 100%), which was replaced at 1–2 min by a modified solution with a divalent cation marked in the legend (see Methods for details). Note that 2 mM of Cd²⁺ or Zn²⁺ increased the emission of either dye, while Ca²⁺ and Ba²⁺ did not. Mean +/− s.e., n > 30 cells per group. Panel C shows fluorescence traces of the response to Zn²⁺ from several individual cells loaded with Fluo-8, without averaging.