Figure 3. Rapid pulsing on the ns timescale.

CHO-K1 cells expressing paxillin-EGFP were fixed and (A) imaged continuously with constant illumination at 40% laser power or with laser pulsing at 80, 50 or 20 MHz. The pixel dwell time and thus the total experiment time was held constant. Normalized decay rates are shown in units of images⁻¹. (B) Normalized photobleaching decay rates when the pixel dwell time was varied to keep the total light exposure at each location within the sample constant. A two-tail t-test of two samples with unequal variances was used to calculate P values. There is no significant difference between 80, 50 and 20 MHz in B. Three stars (***) corresponds to a P values of <0.001. In panel (B) significance is relative to continuous laser illumination in all cases. Error bars are Standard Error of the Mean (SEM).