Summary of dye characteristics.

1Calculated from structures using “Marvin Sketch” software (Chemaxon). Structures of CF dyes are unavailable but charge and logD were calculated by the manufacturer, using the same method. Bold lines indicate divisions between groups of dyes excited at different wavelengths, as follows: Top four dyes, 491 nm; middle seven dyes, 561 nm, bottom three dyes, 638 nm. Laser flux exiting the objective was 3.2 µW/µm2 at 491 and 561 nm, 3.4 µW/µm2 at 638 nm.