General LB Agar after the recipe of Lennox for cultivation of E. coli on agar plates1.
LB Medium is a standard medium for growth and propagation of E. coli. The salt content is suitable for plasmid production, but enables as well the addition of magnesium chloride by phage
amplifications. Ideal for cultures, which need salt sensitive antibiotic e.g. Zeocin.
Composition and Components
Tryptone: 10 g/l
Yeast extract: 5 g/l
NaCl: 5 g/l
Agar: 15 g/l
Storage: Room temperature. recommended storage temperature of powder is +15 °C – +30 °C. Keep container tightly closed, because powder is very hygroscopic.
Solution procedure for 1 l Medium:
1. Fill 900 ml water dest. in an 1-liter flask.
Suspend 35 g powder medium while stirring. Adjust to pH 7 with ca. 0.2 ml 5 N NaOH with stirring, fill up to a final volume of 1 litre.
2. Then autoclave for 20 min. at 121 °C.
3. Cool to 45 °C prior to dispensing into sterile Petri dishes.