Description
Application
ECC ChromoSelect Selective Agar is a selective medium recommended for the simultaneous detection of Escherichia coli and coliforms in water and food samples. The ingredients help even the sublethally injured coliforms to grow rapidly, Tergitol™ inhibits Gram-positive as well as some Gram-negative bacteria other than coliforms. The chromogenic mixture contains two chromogenic substrates as Salmon-GAL and X-glucuronide. The enzyme β-D-galactosidase produced by coliforms cleaves Salmon-GAL, resulting in the salmon-to-red coloration of coliform colonies. The enzyme β-D-glucuronidase produced by E. coli, cleaves X-glucuronide. E. coli forms dark blue-to-violet colored colonies due to cleavage of both Salmon-GAL and X-glucuronide. The addition of tryptophan improves the indole reaction. To confirm E. coli, add a drop of Kovac′s reagent (Catalog No. 60983) on the dark blue-to-violet colony. Formation of cherry-red color indicates the positive reaction.
Preparation Note
Suspend 26.5 g in 1 liter of distilled water. Heat in a boiling water bath or in a free flowing steam, with stirring to dissolve the medium completely (approximately 35 minutes). Medium may show haziness, but it does not affect the performance. If desired to inhibit Pseudomonas and Aeromonas species, add 5 mg of cefsulodin for surface and pour plate method and 10 mg of cefsulodin for membrane filter technique. Mix well.
Suspend 26.5 g in 1 litre distilled water. Heat in a boiling water bath or in a free flowing steam, with stirring to dissolve the medium completely (approximately 35 minutes). Medium may show haziness, but it does not affect the performance. If desired to inhibit Pseudomonas and Aeromonas species add 5 mg Cefsulodin (Cat. No. 22126) for surface and pour plate method and 10 mg Cefsulodin for membrane filter technique. Mix well.
Other Notes
We offer two media types: the superior granulated GranuCult® and the cost-efficient powdered NutriSelect® culture media, depending on your needs.
The designations basic, plus, or prime are added to indicate the quality control level, from basic quality control to standard QC plus to prime for full regulatory compliance.
Legal Information
GRANUCULT is a registered trademark of Merck KGaA, Darmstadt, Germany
NutriSelect is a registered trademark of Merck KGaA, Darmstadt, Germany
TERGITOL is a trademark of The Dow Chemical Company ("Dow") or an affiliated company of Dow
