Capsule expression during biofilm growth conditions in selected strains. Fig. 5A. cpsA, the first gene in the pneumococcal capsule operon is expressed in each isolate over 100-fold relative to R6, an unencapsulated strain (hatched bars), but is downregulated when pneumococcal strains are grown as biofilms (solid bars). Fig. 5B. Immunostaining with anti-capsule specific antibody labeled with a secondary Texas red anti-rabbit antibody, shows that pneumococci express type specific capsule in the biofilm despite cpsA downregulation. Scale bar = 10 μm.