Bacteria grow FAST! In ideal circumstances, some common bacterial cells can divide and double every 20 minutes.
In the following experiment, you are going to use different methods for counting bacteria - Microbiologists use many different ways to "count" bacteria. Some are direct methods, such as counting cells under a microscope ("total count"). Others are indirect methods, e.g. electrical resistance, ATP production). |

- Use a
**direct**method to count the number of cells in a culture of bacteria (viable count). - Use an
**indirect**method to count the number of cells in a culture of bacteria (optical density). - Determine the
**rules**which control bacterial growth: the**growth rate constant**and the**mean generation (doubling) time**.