Harlequin E.coli / Coliform Medium was developed to simultaneously enumerate E.coli and coliforms in food and environmental samples using a dual chromogenic substrate strategy. Tryptone Bile Agar is the base of the medium, which has been modified by the addition of two chromogenic substrates, one to detect the β-glucuronidase enzyme produced by E.coli and another to detect the β-galactosidase enzyme produced by coliforms.
1. Weigh 36.6 grams of powder and disperse in 1 liter of deionized water.
2. Allow to soak for 10 minutes, swirl to mix.
3. Autoclave for 15 minutes at 121°C.
4. Cool to 47°C and mix well.
5. Dispense into Petri dishes.
|Bile Salts No.3||1.5 g|
|Grams per liter||36.6 g|
Final pH: 7.2 ± 0.2