Luria-Bertani (LB) Broth

Reagents (for 1L):

• Tryptone (Bacto, 0123-01-1) – 10g
• Yeast Extract (Fluka, 70161) – 5g
• NaCl (Fisher, BP358-212) – 10g
• DI. Water – 1L
• Enough Screw Top Containers to hold the entire volume

Procedure:

1. Start by adding approximately half of the volume of DI water and a stir bar to an appropriately sized Erlenmeyer flask.
2. Add the yeast extract, NaCl, and tryptone to the water, stirring the entire time.  Make sure to add the tryptone slowly, as this tends to clump.
3. Once those reagents have been completely dissolved, add the remaining volume of DI water to the solution.
4. Distribute the solution into smaller glass jars. The subsequent containers should not be filled above half way. These multiple containers will prevent contamination of the entire stock.
5. Container caps should NOT be screwed on before autoclaving. Just place the cap on top of the container and wrap the top with foil. (NOTE: If caps are screwed onto containers, pressure from autoclaving may cause the containers to burst.)
6. Autoclave for 30-60 minutes using a liquid cycle.
7. Immediately tighten caps when autoclaving has completed.
8. Allow to cool to room temperature and then store at 4°C, until needed.