What is M9 minimal medium?

M9 minimal medium (M9) is commonly used for the cultivation of bacteria (Miller, et al., 1972). It is comprised of a M9 minimal salts base formulation that can be supplemented with various amino acids and carbon sources.

How do you make a M9 medium?

For 50 ml stock solution dissolve 50 mg thiamin-HCl in 45 ml water. Add water to a final volume of 50 ml. Sterilize the solution over a 0.22-µm filter. Prepare 1 ml aliquots and store at -20°C.

What is in M9 medium?

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.

Can E coli grow on M9?

The commonly used M9 medium did not support the optimum growth of E. coli BL21 in minimal medium. The addition of ferrous sulphate to M9 medium (otherwise lacking it) increased the growth rate of E. coli cultures and significantly increased their cell density in the stationary phase.

Why M9 medium is used?

M9 media is a commonly used bacterial media for cultivation and maintenance of Escherichia coli (E. coli) strains. Our Gibco® M9 Minimal Salts (2X) is a concentrated base formulation that can be supplemented with various carbon sources and amino acids to make a complete M9 medium.

Why we use M9 minimal media?

How do you make minimal salt medium?

To prepare minimal medium, add 200 ml sterile 5X Minimal Salts to 750 ml sterile distilled water. Aseptically add 20 ml filter sterilized 20% glucose solution and 2 ml sterile 0.1 M Magnesium sulphate (MgSO4) solution. If desired, add sterile 0.1 ml of 1.0 M Calcium chloride solution or amino acids as required.

Can you autoclave minimal media?

100 mL of 10X M9 salts (60g/L Na2HPO4, 30 g/L KH2PO4, 5 g/L NaCl, pH 7.4, autoclave for sterilization). 2. 10 mL of 100 g/L NH4Cl, pH 7.4 (use 0.22 mM filter for sterilization (since the ammonia is somewhat volatile, autoclaving is not recommended)).

Why is the M9 medium?

M9 medium is a minimal growth medium used for bacterial cultures. It has the advantage of being cheap and has a very low autofluorescence (when excited at 488nm) and also very low absorbance.

What are BL21 cells?

The BL21(DE3) competent cells are an all-purpose strain for high-level protein expression and easy induction. The BL21(DE3)pLysS competent cells provide tighter control of protein expression for expression of toxic proteins and are resistant to chloramphenicol.

What is a culture medium in biology?

Growth medium, also called Culture Medium, or Nutrient Broth, solution freed of all microorganisms by sterilization (usually in an autoclave, where it undergoes heating under pressure for a specific time) and containing the substances required for the growth of microorganisms such as bacteria, protozoans, algae, and …

How do you make mineral salt medium?


  1. For 1x Medium: 3.0 g/l (NH4)2SO4. 3.2 g/l Na2SO4 x10H2O. 0.1 g/l KCl.
  2. For 10x Stock: 30 g/l (NH4)2SO4. 32 g/l Na2SO4 x10H2O.
  3. Add the constituents into a final volume of 1 liter of water, one at a time, dissolving before adding the next.
  4. Adjust the pH to 2.0 with sulfuric acid (and/or sodium hydroxide)
  5. Autoclave.