Figure 1. STEC isolation from various selective media. (A) Cells from enrichment broth are plated on CT-SMAC. (B) Suspect colonies appear as pale on CT-SMAC and steel blue on NT-Rainbow Media, and non-O157 STECs appear as pink colonies on NT-Rainbow (C) Suspect STECS expressing b-galactosidase and hemolysin are indicated by blue colonies with a zone of clearing on Sheeps blood agar (D) Typical non-O157 STECs are shown growing on CHROMagar and appear as blue colonies. Credits: Mike Cooley