FITC-Dextran Feeding: een methode om intestinale permeabiliteit te kwantificeren bij C. elegans

- C. elegans is used as an experimental model of infection by intestinal pathogens which cause disease, in part, by disrupting the intestinal barrier, increasing its permeability. To quantify barrier integrity after exposure to a bacteria or chemical compound of interest, collect worms by washing them off their plates.

Next, place these worms on agar plates with labeled food composed of heat-killed E. coli mixed with FITC-dextran, a high molecular weight polysaccharide with a fluorescent tag.

Allow the worms to eat the labeled bacteria. Those with intact intestinal barriers will rapidly clear the food, while in worms with more permeable intestines, the fluorescent marker will penetrate beyond the lumen of the organ.

Transfer worms to a formaldehyde solution to fix the animals. After 1 to 2 minutes, replace the formaldehyde with mounting media.

Finally, image the worms by fluorescent microscopy. Note that C. elegans intestinal granules are autofluorescent, so there will be background signal. But overall, more intestinal fluorescence indicates higher permeability.

In the example protocol, we will assay the effect of treatment with the biomolecule DIM on the intestinal permeability of