Figure 7: Frozen tissue sections of the femoral muscle, liver, lung, and spleen. The Dio-labeled and Hoechst 33342-incorporated PLGA particles were locally injected into the femoral muscle or introduced intravenously through the caudal vein. The femoral muscle ((a), (b)), liver ((c), (d)), lung ((e), (f)), and spleen (g) were removed 3 days after administration of the particles. Cryostat sections were observed by phase contrast ((a), (c), and (e)) or fluorescent microscopy ((b), (d), (f), and (g)). Green, blue, and orange colors represent particles labeled with Dio ((b), (d), (f), and (g)), nuclear staining with Hoechst 33342 ((b), (d), (f), and (g)), or plasma membrane stained with CellMask Plasma Membrane Stain (g), respectively. Bars indicate 10 μm. Note that nuclear staining is only observed around the particles.