产地:oxoid 货号:CM0505B Description MacConkey Broth has long been used as a presumptive medium for the detection of the coli-aerogenes organisms. In the original medium, litmus was employed as the indicator of acid production but, in later publications, MacConkey suggested neutral red as a more satisfactory alternative. Childs & Allen1 showed that some samples of neutral red exerted an inhibitory effect on the growth of Escherichia coli in this medium. Bromocresol purple is less inhibitory, and the colour change from purple to yellow provides a more sensitive and definite indication of acid formation; therefore this indicator is used in Oxoid MacConkey Broth (Purple), which corresponds to the alternative formulations recommended in `The Bacteriological Examination of Water Supplies’2 and `International Standards for Drinking Water’3. Storage conditions and Shelf life Store the dehydrated medium at 10-30°C and use before the expiry date on the label. Store the prepared medium at room temperature.