Please contact Dr. Steven Wilhelm (wilhelm@utk.edu) for additional information regarding this protocol.Modified from Rioux, C., Jordan, D., & Rattray, J. B. (1983). Colorimetric determination of catechol siderophores in microbial cultures. Analytical Biochemistry,133(1), 163-169. doi:10.1016/0003-2697(83)90238-5