Measure the Biofilm Formation of Salmonella Using Crystal Violet Assay

Salmonella can form biofilms, which are structured microbial communities composed of cells that adhere irreversibly to surfaces or to other cells. The formation of Salmonella biofilms may enhance the bacterial resistance to drugs, environmental stress, and the host immune system. Crystal violet staining is one of the most classical and widely used methods for measuring biofilms in laboratories. Its principle is primarily based on the binding of crystal violet to various components within the biofilm. Here, we describe the crystal violet assay protocol to measure the formation of Salmonella biofilms in laboratory conditions, including growth in a microplate and in a glass tube.