Figure 3

Diffusion-limited FLIP of eGFP in the cytoplasm of McA cells. McArdle RH7777 cells expressing eGFP in the cytoplasm and nucleus were placed on a temperature-controlled stage of a confocal microscope maintained at 35 ± 1°C. A 10 pixel diameter circular region in the cytoplasm (white circle) was repeatedly bleached with full laser power, while the whole field was scanned with 0.5% laser output between the bleach scans. This gave a total frame rate of 1.6 sec (see Methods for further details). A, montage of the time series with every 20^th frame shown. B-D, fit of the StrExp function to the data giving a map of the stretching parameter (B), the time constant map (C) and its reciprocal, the rate constant map (D). A FIRE-LUT was used for color-coding, where dark blue and yellow indicate lowest and highest values, respectively. The range of values is given below the images with a color bar without units in B, in sec in C and in sec^-1 in D. Bar, 5 μm. E, profile of stretching parameters along the line shown in B (grey line, data; black line moving average to smooth the profile).