Transfer
of
Fresh
Media
Microbial cultures can be maintained by periodic transfer on fresh, sterile media in tubes. The frequency of transfer however varies with the organisms. For example, a culture of E. coli needs to be transferred at monthly intervals. After growth for 24 hours at 37°C, the slants can be stored at low temperature for 20-30 days. To keep the
cultures viable, it is necessary to use an appropriate growth medium and a proper storage temperature. Many heterotrophic bacteria can be maintained on a medium such as nutrient agar with transfers to fresh medium after every 20-30 days.
