3M™ Petrifilm™ E. coli/Coliform Count Plates

The 3M Petrifilm E. coli/Coliform Count Plate is a ready-made culture medium system which contains Violet Red Bile (VRB) nutrients, a cold-water-soluble gelling agent, an indicator of glucuronidase activity, and a tetrazolium indicator that facilitates colony enumeration.

The red indicator dye in the plate colors all colonies red, and the top film traps gas produced by the coliforms. In addition, a glucuronidase indicator forms a blue precipitate around any E. coli colonies that may be present.

Like most other E. coli/coliform media, this plate will not specifically indicate whether any O157 strain is present. Please note that E. coli O157:H7 is glucuronidase negative and will not produce a blue precipitate.