Immunofluorescence for CD68 detection

After deparaffinization and rehydration, 5‐μm lung tissue sections on the slides were incubated with 1% BSA in PBS for 30 min. Slides were incubated overnight at 4°C with anti‐CD68 antibody (1:100), then followed by 1 hr incubation with a FITC‐labelled secondary antibody (Santa Cruz) at 37°C. The nucleus was stained with 4′,6‐diamidino‐2‐phenylindole (Beyotime Biotech) for 5 min. in room temperature. The images were viewed under a fluorescent microscope (400× amplification; Nikon).