Figure 3. Relative differences in protein expression between human corneal endothelial cells cultured from young and older donors. The same 2-D gel from the young donor shown in Figure 2C has been enlarged and color-coded by the analysis software to indicate individual proteins spots that show differences in relative protein expression. Spots with no color designation indicate similar expression within a twofold range. Green indicates spots that were increased by twofold or greater in cells from young donors compared to older donors. Red indicates spots that were twofold decreased in young donors compared with older donors. Blue shows those spots that were present in extracts from young donors but were not detected in extracts from older donors.