These are digital fluorescence images of confluent bulk-selected HeLa cells that stably express wild type Cx26 (Cx26WT) or the indicated Cx26 mutants. The cells were incubated in 0.1% Lucifer Yellow (LY, upper row) or 2% neurobiotin (NB, lower row), imaged (LY) or fixed (NB, then visualized with TRITC-conjugated avidin) ~15 min after being wounded with a scalpel blade. Note that the wounded cells picked up LY or NB in all cases, but only cells expressing Cx26WT showed extensive transfer of LY or NB to neighboring cells. Scale bar: 50 μm.