Selectively isolate Yersinia enterocolitica using Thermo Scientific™ Remel™ CN Selective Supplement (Cefsulodin, Novobiocin). This supplement is used in the preparation of CIN agar base which makes it selective and a differential medium for isolation of Y. enterocolitica. Supplementation with CN supplement improves inhibition of normal enteric organisms such as Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis and Pseudomonas aeruginosa, as well as gram-positive organisms.