M9, Minimal Salts, 5X

M9 Minimal Salts is a highly-referenced microbial growth medium used for the cultivation of E. coli. This buffered minimal microbial medium contains only salts and nitrogen, so it is traditionally supplemented with glucose, amino acids and vitamins as needed.

M9, Minimal Salts, 5X has been used:

• in a selective agar medium for the isolation of sulphate reducing bacteria
• in GMML minimal media to propagate phage-resistant DH10B cells
• in M9 minimal medium which is used for cell motility assay

M9 Minimal Salts 5x are suitable for the preparation of M9 Minimal Medium for use in propagation of E. coli and plasmid amplification. It is suitable for non-selective cultivation of E. coli strains for cloning, DNA plasmid production and production of recombinant proteins. Also suitable for maintaining positive selection pressure on E. coli that produce essential amino acids and for maintenance of F′-containing bacteria strains for M13 propagation.

M9 powder provides:

• Standard formulation
• A budget-friendly alternative to liquid

1. Dissolve 56.4 g in 1L of distilled water.
2. Autoclave for 15 minutes at 121°C.
This convenient 5× concentrate can be stored and diluted as needed to prepare 5 L of 1× M9 minimal salts.

For M9 minimal medium:
1. Aseptically dilute 200 ml of M9 minimal salts, 5× concentrate with 800 ml of sterile water. If necessary, cool to 45-50°C.
2. Aseptically add 20 ml of sterile 1 M glucose and 2 ml of sterile 1 M magnesium sulfate to prepare 1 L of M9 minimal medium.
3. If desired, aseptically add 0.1 ml of 1 M sterile calcium chloride to the M9 minimal medium. The M9 minimal medium may also be supplemented with the appropriate amino acids.

Make a 5x concentrated stock solution by stirring to suspend 56.4g powder in 1L water. Autoclave for 15 minutes at 121°C to sterilize. Allow to cool before making additions, such as antibiotics (if desired).

Dilute the 5x M9 concentrated stock to a 1x working solution by adding 200mL 5x M9 stock to 800mL sterile water. If needed, allow to cool before making additions, such as antibiotics (if desired).