Microbiology of food and animal feeding stuffs. Horizontal method for the enumeration of β-glucuronidase-positive Escherichia coli. Part 2. Colony-count technique at 44 °C using 5-bromo-4-chloro-3-indolyl β-D-glucuronide
State system for ensuring the uniformity of measurements. The cells for the reference points of the temperature scale. Standard procedure for verification and calibration