Culture medium and device using ballasted pH indicators for detection and enumeration of microorganisms

摘要

Media, devices and methods using ballasted pH indicators to detect and enumerate bacterial colonies in a sample are described. The ballasted pH indicators limit the diffusion of the indicator or fluorescent indicator zones associated with the growing microbial colonies in the medium. In addition, the ballasting of certain typically toxic indicators may render these indicators harmless to bacteria without adversely affecting their pH indicating ability.