After 3,5 h of growth (37°C, anaerobic conditions) the supernatant was completely removed and replaced with fresh THBS-medium containing 200 nM CSP and/or 2 μM carolacton. Untreated cells were used as reference samples. At least three wells were used as replicates for each condition tested. Samples were harvested at different time points following supplementation of CSP and/or carolacton using a rubber scraper. Scraped off cells were resuspended in 200 μl of THBS and the luciferase assay was performed

as described above. Confocal Laser Scanning Microscopy Biofilms developed on half area 96-well polystyrene flat-bottom microtiter plates for 12 or 23 h in triplicate and stained with the LIVE/DEAD BacLight viability kit (see above) were observed using an Olympus FlowView 1000 (Olympus, Tokyo, Japan) confocal laser scanning microscope. To acquire green (“”live”") H 89 order and red (“”dead”") fluorescence,

respectively, a laser excitation at 488 nm (Ar laser) and 561 nm (He laser) and AZD2014 emission filters at 500 – 545 nm and 580 – 680 nm were used. Image data were subsequently processed with the Imaris software (Bitplane AG, Zürich, Switzerland). Acknowledgements The authors thank Prof. Dr. D.G. Cvitkovitch (University of Toronto, Canada) for providing the S. mutans strains, Birte Engelhardt and Bettina Elxnat for skillful technical assistance, Dr. Florenz Sasse for performing CYTH4 mammalian cell culture tests, Dr. Helena Sztajer for many helpful suggestions and members of the chemical pipeline for providing secondary metabolites from myxobacteria. References 1. Costerton

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