EC Medium was developed by Hajna and Perry to differentiate between fecal and non-fecal coliform bacteria. It is a buffered lactose broth which also contains bile salts which inhibits Gram positive cocci and spore formers. It was designed to improve the isolation and detection of E coli in contaminated water, milk and shellfish. APHA recommends that EC Broth be used for the determination of water pollution. Coliforms of fecal origin are detected by growth at 44.5°C. Fermentation of lactose is observed by gas bubbles present in an inverted fermentation tube.
Used in the isolation of E. coli from water, milk and shellfish and differentiation of coliform bacteria at 37°C and E. coli at 45.5°C
Components shown as g/liter
Casein Digest of Peptone20.0Lactose5.0Sodium Chloride5.0Bile Salts Mixture1.5Monopotassium Phosphate1.5Disodium Phosphate4.0Total:37g/liter
Directions per Liter:Dissolve 37g in 800-900ml of ddH2O stirring gently with heating until completely solubilized. Adjust pH of the medium to the desired level. Add additional water to bring the solution to1L. Dispense into appropriate containers, loosen caps and autoclave for 15 minutes at 121ºC (15psi).
Storage and Stability:Store powdered media at 4°C. Opened bottles should be capped tightly and kept in a dark, low humidity environment. Prepared media should be kept at 4°C and used within a short period of time
Microbiological Analysis:Escherichia coli ATCC 25922: Growth Gas (+)Escherichia coli ATCC 11775: Growth Gas (+)Enterococcus faecalis ATCC 29212: Inhibited Gas (-)
Important Note: This product as supplied is intended for research use only, not for use in human, therapeutic or diagnostic applications without the expressed written authorization of United States Biological.
