FITC Anti-Mouse CD11c Antibody on Mouse Cells

I want to identify lymphocyte populations in bacteria infected lung. We use the CD11c antibody as one of the markers for the lymphocyte population. C57Bl/6 mice were infected for 24 hours with E coli and the mice were lavaged with 2 ml of PBS. After lavaged, the BALF samples were spun @ 700G for 10 mins @ 4 degrees. After centrifugation, the supernatant were removed and the cells pellet were stained with the CD11c antibody for 20 mins on ice at 1:200 dilution. Following staining, cells were fixed with 2% PFA for 20 mins and washed with PBS. Then, cells were subject to FACs.