A Minimal Medium is a chemically-defined growth medium. It can be used to culture Escherichia coli. It is prepared as a concentrated medium without supplement which is diluted to a working solution and supplemented with appropriate carbon and energy source, and some trace elements.
The following section describes a procedure to prepare 1000 ml of A minimal medium.
Reagents and solutions
5x A Minimal Medium (without supplements)
20% Glucose or Glycerol
1 M Magnesium sulfate (MgSO4)
0.5% vitamin B1 (thiamine)
20% Casamino Acids
Equipment and disposables
Conical flask / Beaker
Composition of A Minimal medium
1x A Minimal media (without supplements)
1 mM MgSO4
Preparation of 1000 ml of A Minimal medium
Step 1: To prepare 1000 ml of A Minimal medium, take 700 ml water in a 2-liter beaker. Add 200 ml 5x concentrated A medium (without supplements), 10 ml of 20% Glucose or Glycerol, and 1 ml of 1M MgSO4. Mix.
Note: if required, 0.1 ml 0.5% vitamin B1 (thiamine), 5 ml 20% Casamino Acids, and antibiotics can be added.
Step 2: Adjust the volume to 1000 ml with deionized water. Mix it again.
Step 3: Sterilize the solution by filtering through a filter unit containing a membrane with pore size 0.22 or less under aseptic conditions.
You don’t need to filter-sterilize the solution if you have used sterile reagents and glasswares and handled them aseptically.
Store the solution in fridge (2 – 8°C)