occurs when a large number of tubes were immersed. After
heating, the tubes were immersed in chilled water immediately.
The survivors in the heated TDT tubes were determined
by using liver broth as the growing medium. The
positive tubes in each of the three rows were recorded
after incubation at 27–30 °C for a period of 8 weeks
and results were interpreted using 3 test tube MPNMethod
(APHA 1984).