Fluorescence and phase contrast micrographs of S. iniae showing binding of biotinylated fibrinogen. Strains QMA0072, QMA0076 and QMA00141 were incubated with biotinylated human fibrinogen, extensively washed and subsequently labelled with FITC-conjugated streptavidin. In each case panel A) indicates bacteria incubated with biotinylated fibrinogen, extensively washed and then stained with streptavidin-FITC under fluorescence, whilst B) is the same field photographed under phase contrast. Panel C) indicates control bacteria, incubated in PBS, extensively washed and stained with streptavidin-FITC to detect any non-specific binding of streptavidin, or autofluorescence whilst D) is the same field observed under phase contrast. For fluorescence microscopy, all fields were exposed manually at ISO800 for 1.3 seconds whilst phase contrast fields were captured using automatic exposure.