Fig. 2. Differential interference contrast (DIC), fluorescence, and overlay images of HeLa cells stained with (E)-2/(Z)-2 and (E)-3/(Z)-3 and Hoechst 33342. The cells were first incubated with (E)-2/(Z)-2 and (E)-3/(Z)-3, which were observed using 405/700 channel. Hoechst 33342 was then added and imaged after 10 minutes using 405/430 channel. Scale bar = 10 μm.