Confocal laser microscopy on biofilms: Successes and limitations

Abstract

Imaging of bacterial biofilms with microscopes has been an essential and transformative method in biofilm research. Fluorescence microscopy can elucidate specific biofilm components and cellular activities that cannot be separated otherwise. In particular, confocal fluorescence microscopy extends that examination through the thickness of a fully hydrated, in-situ biofilm, affording the potential for 3D, non-invasive, time-lapse imaging. This article discusses some striking examples of the insight provided by confocal fluorescence microscopy into biofilm structure, composition, and heterogeneity, and will also enumerate some limitations of this imaging process.