Protocol for LB liquid medium:
- For 1 liter, dissolve 10 g Tryptone, 5 g yeast extract, and 10 g NaCl in 950 ml deionized water.
- Adjust the pH of the solution to 7.0 with NaOH and bring the volume up to 1 liter.It may not be necessary to adjust pH every time, since pH of LB naturally close to pH 7.0. This might be affected by your yeast extract.
- Autoclave on liquid cycle for 20 minutes at 15 psi. Allow solution to cool to 55 C and add antibiotic if needed.
- Store at room temperature or at 4°C if antibiotic is added.