Figure 6

Determination of the rate of increase of cellular fluorescence level at three points in the time series of Figure 5 . The time series are confocal fluorescence images acquired before and during x-ray radiation (Additional file 2). (a) In a typical time series, the rates of fluorescence increase are illustrated by the green straight segments. The rate prior to the on-switch of the x-ray beam was calculated from the slope of the first 5 images. The rate at the onset of x-rays was calculated from the increase between the 5^th and 6^th images. The rate at 5 minutes of radiation was calculated between the 14^th and 15^th images. (b) The average and standard deviation of the rates of fluorescence increase are graphed for the three time points, among four separate experiments.