Figure 1
Estimate of hCx26wt unitary permeability to calcein in pairs of transfected HeLa cells. (A) Average fluorescence traces (n = 3) obtained by illuminating the field at λex = 465 nm to observe calcein spread (emission wavelength λem = 520 nm); calcein (125 μM) was delivered to cell 1 under whole−cell recording conditions (WC1); ordinates are calcein concentration (see Methods); triangles correspond to cell 1, dots to cell 2; bars represent standard error of the mean (SEM). To better appreciate the rise in fluorescence in cell 2, the inset on the right shows a close − up view between WC1 and the time of achieving the whole–cell configuration in cell 2 (WC2). (B) The junctional conductance (g j ) value required to estimate the single channel permeability pu to calcein was back extrapolated from the time course of g j after WC2. (C) The value of pu = 3.0 ± 1.0 (mean ± SEM) was computed in the interval between times t1 and t2 where the signal–to–noise ratio was optimal.