Luria Broth (LB) Preparation

LB-liquid

1. Weigh 25 g of Luria Broth Base powder.

2. Add the powder into 1 L of water.

3. Swirl to mix with a stir bar for 10 minutes.

4. Cover the top of the flask with aluminum foil and label with autoclave tape.

5. Autoclave on the liquid setting for 30 minutes.

6. After removing the solution from the autoclave, allow the agar solution to cool to 55°C.

LB-Solid

1. Weigh 40 g of Luria Broth Base powder.

2. Add the powder into 1 L of water.

3. Swirl to mix with a stir bar for 10 minutes.

4. Cover the top of the flask with aluminum foil and label with autoclave tape.

5. Autoclave on the liquid setting for 30 minutes.

6. After removing the solution from the autoclave, allow the agar solution to cool to 55°C.

7. Add the appropriate amount of desired antibiotic to the solution and swirl to mix.

8. Pour ~20 mL of LB agar per 10 cm polystyrene Petri dish.

9. Place the lids on the plates and allow them to cool for 30-60 minutes (until solidified).

10. Invert the plates and let sit for several more hours or overnight.

11. Label the bottom of plates with antibiotic and date and store in plastic bags or sealed with parafilm at 4°C.