LB selection plates

  1. Dissolve 32 g of LB agar powder in 800 mL of sterile/ELGA water.

  2. Autoclave on 20 min liquid cycle at 121C.

  3. Wait for the solution to cool to about 45-50 C by letting it sit on a bench (room temperature).

Tip

If you can keep touching it with bare hands, that indicates the temperature of the LB is around 45-50C and it’s time to add antibiotics.

  1. Add 800 uL of 1000x antibiotics to the autoclaved LB agar-water solution.

  2. Dissolve the antibiotics by stirring with a stir bar.

  3. Before pouring, ensure no agar has solidified in the bottle (as a result of uneven cooling). If this happens, shake manually to re-melt the agar.

  4. Pour 20-25ml of the antibiotic-containing LB to petri dishes using a pipette.

Tip

Alternatively, you can pour LB by hand if you experience solidification when pipetting.

  1. Incubate the poured plates at RT until the LB agar solidifies (normally takes about 30-45min).

  2. After plates solidify, place plates back in the sleeve bag and store at 4C.