m-TGE (Tryptone Glucose Extract) is a non-selective medium used for the determination of heterotrophic plate counts by the membrane filtration method and specified by the American Public Health Association for the heterotrophic plate count procedure in testing bottled water. Also used for isolation, detection and cultivation of wide variety of microorganisms in beverages, ground, surface and recreational waters, milk, and other dairy products. All colonies that grow on the surface of the membrane are counted and recorded. Because m-TGE is a non-selective medium (supports the growth of various bacteria), a range of different colony appearances may be seen in a single sample. Typically, plates are incubated at 35°C ± 2°C for 24-48 hours (with longer incubation times recommended for bottled water).