Fig. 3

a Effects of illumination on the fluorescence/absorption background intensity of the dye. The ordinate represents the relative fluorescence/absorption intensity (DC-background light intensity at each time divided by that at time 0), and the abscissa is the time of continuous illumination. b Effects of perfusion on the fluorescence/absorption background intensity of the dye. The incident light was turned off except during the measuring period. The ordinate represents the relative fluorescence/absorption intensity (DC-background light intensity at each time divided by that at time 0). The lower abscissa is the time after staining (perfusion rate: 1 ml/min), and the upper abscissa is the total illumination time. In each figure, the results of an absorption dye (NK2761) and three fluorescence dyes (di-4-ANEPPS, di-3-ANEPPDHQ, and di-2-ANEPEQ) are shown. Modified from Ref. [24]