Growth rate determination of E. coli
Ashwinuday
Abstract
This is to measure the growth rate of E. coli.
The initially used culture is a primary culture.
This can be adapted for any other bacteria as well by giveing proper growth conditions, and using appropriate wavelength to measure the OD and giving proper time intervals based on whether the bacteria is slow growing or fast growing.
Before start
Keep an overnight grown culture ready.
Steps
Grow the bacteria in an overnight (14-18 hours) culture.
Inoculate 50 ml autoclaved culture media in a conical flask with a part of the overnight grown culture equal to 2% volume of fresh media (i.e. 1ml) inside a laminar hood.
Mix the contents well and take 1 ml of the media into a clean cuvette and measure its OD at 600nm in a spectrophotometer.
This will serve as the 0 hour reading.
Put the rest of the freshly inoculated flask into a shaking incubator at 180rpm at 37°C.
At every 1 hour take out the flask, open inside a hood, mix well, quickly take 1 ml of the culture into a cleaned cuvette and again measure its OD at 600nm.
Note down the OD till 20 hours. Then plot a graph of OD v/s time.
