In recent decades the scientific community has started to appreciate that most microorganisms live in complex 3D structures composed of cells, polysaccharides, and other components such as proteins, extracellular (e)DNA, and lipids. These structures are commonly designated 'biofilms'. Similar to other areas of research, biofilm studies have been affected by a lack of reproducibility. In this article, we propose a new scheme on how to classify the level of reproducibility in biofilms. This consists of four different levels: level 1, no reproducibility; level 2, standard reproducibility; level 3, potential standard reproducibility; and level 4, total reproducibility. Some methods aim to improve reproducibility by focusing on biofilm growth reactors, while others focus on biofilm characterization methods. Moreover, initiatives such as minimum information guidelines and biofilm-centered databases offer alternative strategies to tackle the reproducibility problem. The path to total reproducibility is certainly complex, but novel experimental and computational strategies are bringing us closer to achieving this goal.
