Fig. 4: Calibration of optical instruments.
a,b, The dependence of the light intensity at 488 nm (a) and 625 nm (b) on the percentage scale available on the instruments (confocal microscope with pulsed laser in a and fluorometer in b) has been established with the Dronpa-2-labeled nucleus of a fixed U-2 OS cell (mean value ± s.d., s.d. are propagated from the error on σ(488) (20 repeats)) and photosynthetic apparatus actinometers, respectively. T = 293 K (text and Supplementary Tables 1 and 2).
