Figure 1. Calcein as a cytoplasmic “metal detector”.

(A): two electrode voltage clamp of a representative rDMT1 transfected oocyte; inward currents are induced by 100 μM MnCl₂, FeCl₂ and CoCl₂ (V_h = −40 mV, pH 5.5). (B): means and standard errors of the transport currents obtained from 40 oocytes, five batches. (C–E): Plots of fluorescence decay (F_t/F₀) with corresponding images of Calcein-injected oocytes (upper series: non-transfected (NT) and lower series: rDMT1 transfected) exposed to 100 μM MnCl₂ (C), FeCl₂ (D), and CoCl₂ (E) at pH 5.5 from 3 to 10 oocytes, from 2 to 4 oocytes batches.