16 Aug 2013 --- Symrise BioActives and Gee Lawson are extending a cooperation, which began in 2011. Symrise BioActives manufactures highly purified esculin, which Gee Lawson supplies to the diagnostics industry. Esculin is used in microbiology culture media to reliably identify contamination from species such as streptococci and listeria, and so can be used to monitor food and water as well as the clinical testing of patients.