Fig. 2 Recovery curves in FRAP experiments. Fluorescence intensities normalized by the initial value just before photobleaching were plotted against time. The data points and error bars indicate the mean ± s.d. For simplicity, error bars are indicated only for every five points. Theoretical curves (solid lines) obtained by fitting data to Eqn 1 are superimposed. Arrows indicate the time points of photobleaching. (A–C) Recovery curves of flagella loaded with (A) calcein, (B) carboxyfluorescein and (C) Oregon Green (N=6). (D) A typical curve of FRAP in aqueous solution in the case where calcein in 10 mmol l^–1 HEPES (pH 7.0) and 20% glycerol (N=3) was used. (E) Fluorescence recovery in heads (open squares) and concomitant fluorescence decrease of whole flagella (open circles) when a photobleaching laser pulse was directed to the head region (N=5). Note that the data are shown with a longer time scale than for the other four.