The composition of this medium complies with the recommendations of the American Public Health Association for
the examination of water (1998) and foodstuffs (1992), and with the recommendations of the United States Pharmacopeia XXVI (2003) and the European Pharmacopeia II for the examination of pharmaceutical products and raw materials.
Mode of Action
Lactose utilization is indicated by gas production. The gas liberated is collected in DURHAM tubes.
Typical Composition (g/litre)
Peptone 5.0; meat (beef) extract 3.0; lactose 5.0.
Suspend 13 g or more/litre (see Table), dispense into test tubes fitted with DURHAM tubes, autoclave (15 min at 121 °C).
pH: 6.9 ± 0.2 at 25 °C.
The prepared broth is clear and yellowish.
Experimental Procedure and Evaluation
Mix 1, 10 or 100 ml samples with the specified volumes of lactose broth. The initial concentaton of the lactose broth must be increased so that the final concentration of the components is maintained at a constant level (13 g/l). See table
|1||10 or more||11 or more||13||1-fold|
Incubation: 24-48 hours at 35 °C aerobically.
Check the DURHAM tubes for gas production.