Multiple colored variants of a strain of Vibrio cholerae (a causative agent of cholera in human hosts) co-inoculated on glass. The variants express 3 different fluorescent proteins that enable visualization of the contribution of each to biofilm formation. One optical slice at the base of a biofilm is shown in two of these images, while the 3-D volume snapshot was rendered using a z-stack of optical slices of the biofilm.  Biofilm formation can affect virulence and persistence of this important human pathogen.