Fig. 3. Quantitative analysis of the distribution of cytochrome c and mitochondrial diameter change. (A,B) Magnified images of Mitotracker before (A) and after (B) mitochondria swelled. (C) The diameter of a mitochondrion was taken as the half width of its pixel profile based on a line-scan measurement of the Mitotracker image. (D) The distribution profiles of cytoc-GFP fluorescence intensity in a region containing only cytoplasm (left), or in a region containing both cytoplasm and mitochondria (right). The arrow marks the threshold that separates the fluorescence signal contributed by cytoc-GFP located in the mitochondria from that of the cytosolic cytoc-GFP.