Predominant P. aeruginosa biofilm structures depend on contact lens materials after 72 h growth. Transmitted light micrographs: deposits and adherent bacterial cells on the contact lenses are visible as grey dots and shadows. CTC staining of the biofilms (red) shows the metabolic activity of viable bacteria cells. ConA Alexa Fluor 488 staining of the biofilms (green) verifies the presence of alginate within the biofilm matrix. Superimposition of the transmitted light micrographs and the fluorescence micrographs (merge) shows the correlation of the CTC and ConA Alexa Fluor 488 staining regions. Bar = 20 μm.