mFS (modified Fieldhouse Sasser medium) has been developed to detect black rot in brassica. This medium is complementary to mCS20ABN (C5122) due to some alternative antibiotics. Modifications concern the addition of extra starch and omission of gentamycin.Contaminated seed lots can be detected by dilution plating of the bacterial extract on mCS20ABN and mFS. Suspected isolates are then transferred to YDC. Finally, the identity of the suspected isolates can be determined by a pathogenicity test using brassica seedlings.The colonies of Xanthomonas campestris pv. campestris (Xcc) and Xanthomonas campestris pv. amoraciae (Xca) on mFS medium are pale green to transparant, mucoid and surrounded by a small zone of starch hydrolysis. Colonies are in general smaller than on mCS20ABN and may show remarkable variation in size and may be visible only after 5-6 days. For detailed information about Duchefa’s Phytopathological media have a look at our specialized brochure about this topic. Brochure can be found at the “Brochure section” at the home page of this website.