Biofilms are found in various environments. They are aggregates composed of microorganisms and their metabolites, such as extracellular polysaccharides. In recent years, there has been an increasing need to evaluate the amount of biofilm formed on materials, as well as an increasing need for drugs that inhibit biofilm formation. The Biofilm TestPiece Assay Kit uses crystal violet staining to measure the difference in biofilm formation among different materials. By using the Dojindo-developed lid, “TestPiece Holder”, a test piece can be firmly fixed, and the biofilm will not peel off during washing or staining processes. As well, multiple samples can be assayed simultaneously. Dojindo offers various reagents for bacteria research. (https://www.dojindo.com/observe-bacteria-from-various-parameters/)