Source: Nickerson, K. P., et al. Bile Salt-induced Biofilm Formation in Enteric Pathogens: Techniques for Identification and Quantification. J. Vis. Exp. (2018).
This video demonstrates a fluorescence-based method for quantifying bile salt-induced biofilm formation. Upon the addition of bile salts in the culture of a pathogenic enteric bacteria, biofilm production is detected using a fluorescent lectin that binds to the polysaccharides in the extracellular polymeric substance (EPS) matrix of the biofilm.
1. Preparation of Reagents
2. Preparation of Bacteria
3. EPS Matrix Detection
NOTE: These complimentary assays quantify and visualize the EPS. In both, EPS is detected using a lectin to bind polysaccharides. The fluorescently-conjugated protein allows quantification.
The authors have nothing to disclose.
Tryptic Soy Broth | Sigma-Aldrich | 22092-500G | |
Concanavalin-A FITC | Sigma | C7642-10mg | |
Glucose | Sigma | G7021-1KG | |
Bile Salts | Sigma | B8756-100G | |
LB Agar | Sigma | L7533-1KG | |
14 mL culture tubes, 17 x 100 mm, plastic, sterile | Fisher | 14-959-11B | |
Vectashield hard-set antifade with DAPI | Vector Laboratories | H-1500 | |
Formaldehyde | Sigma-Aldrich | F1635-500 | |
Gluteraldehyde | Sigma-Aldrich | G6257 | |
Flat-bottomed 96-well plates (clear) | TPP | 92696 | |
Flat-bottomed 96-well plates (black) | Greiner Bio-One | 655076 | |
Flat-bottomed 24-well plates (clear) | TPP | 92424 | |
96-well plate reader | Spectramax | ||
Flourescent plate reader | Biotek Synergy 2 | ||
Confocal or Fluorescent Microscope | Nikon A1 confocal microscope | ||
37°C Shaking Incubator | New Brunswick Scientific Excella E25 | ||
37°C Plate Incubator | Thermolyne Series 5000 |