Color enhanced Scanning Electron Micrograph (SEM) image of a Staphylococcus biofilm was based on the culture obtained from the inner surface of a needle-less connector. A biofilm is any group of microorganisms in which cells stick to each other and often also to a surface. These adherent cells become embedded within a slimy extracellular matrix that is composed of extracellular polymeric substances (EPS). The EPS components are produced by the cells within the biofilm and are typically a polymeric conglomeration of extracellular DNA, proteins, and polysaccharides. These polysaccharides have been visualized by scanning electron microscopy. Magnification: 2363x.