Figure 4. Immunofluorescence microscopy analysis of p62 (red) and ubiquitin (green) in ARPE-19 cells. Cells were exposed to 5 µM MG-132 with nonsilencing siRNA or with p62 siRNA (both 30 nM) for 24 h. Nuclei are stained with blue dye. Arrows point to the colocalization of p62 and ubiquitin in perinuclear protein aggregates.