Scientific Background

Giuseppe Bertani published the original formula of LB, which is used for the cultivation of E. Coli. It provides the main essential nutrition, containing peptides. For transformation, we use LB agar but for small and big cultures we use the original liquid LB


The presparation is to dissolve LB powder in distilled water, and autoclave it.


LB Broth (1 L)

  1 L dH20 ;  20g LB powder ;  a 1 l bottle ;  measuring cylinder ; Laboratory scale


1) Take a jar of LB powder

2) Measure 20 g of LB powder in a scale ( it depends on the amount of LB you need, take 10 g if you’d like to make 500ml of a LB medium )

3) Put the powder into a 1 liter flask or bottle, (again, depends on how much you need)

4) Add the distilled water into the bottle till it reaches 1 liter

5) Shake it

6) Close it and stick a tape from one side of the wall vertically over the cap to the other side of the wall (which means not sterile) which will be black striped after autoclave sterilization

7) Sterilize the bottle (autoclave)