Figure 2. Detecting chitinase activity with a chitin azure colorimetric assay. Chitinase activity can be detected using tubes containing two layers of agar: a top layer consisting of a basal medium with chitin azure, and a lower layer with only the basal medium. When chitin-azure is hydrolyzed in the top layer, the dye diffuses into the lower layer indicating chitinolytic activity. Pictured are two controls used in a chitinase assay, the tube on the left was inoculated with water, while the one on the right was inoculated with a bacterial suspension of a known chitinolytic strain closely related to Paenibacillus tundrae.