Titration of antibody reactivity of anti-Legionella pneumophila antiserum by direct ELISA Plate was coated with 100 μl of 109 cells/ml per well and 100 μl of the antiserum at the indicated dilution was added to each well and incubated. After washing, goat anti-rabbit-IgG conjugated with HRP was added as 2nd antibody. Color was developed with TMB as substrate. "pre" is preimmune serum and "Immunized" is immunized serum

Immunofluorescent staining of Legionella pneumophila in the infected HEK293 cells using anti-Legionella pneumophila antibody. HEK293 cells were infected with Legionella pneumophila strain Philadelphia1 fixed with 4% formaldehyde and reacted with the anti-Legionella pneumophila antibody at 1/10,000 dilution. As the second antibody, goat Rodamine Red X conjugated anti-rabbit IgG antibody was used at 1/10,000 dilution. DNA was stained with Hoechst 33342 (center) and the images were merged with that of differential interference contrast microscope (right).