Visualizing biofilm by targeting eDNA with long wavelength probe CDr15Electronic supplementary information (ESI) available: Experimental procedures, supplementary tables, figures and spectra. See DOI: 10.1039/c9bm00152b

Detection of the biofilm of bacteria would be a counter strategy to detect hidden bacteria in their camouflage. Through unbiased screening of bacteria biofilm, we discovered a long wavelength probe CDr15 with extracellular DNA as the molecular target. CDr15 revealed a real-time geometric distribution of eDNA in a 3D bacterial colony.