LB agar
Agar (20 g/L)
NaCl (10 g/L; Sigma-Aldrich S9625)
Tryptone (10 g/L; BD 211705)
Yeast extract (5 g/L; BD 212750)
Add H2O to a final volume of 1 L. Adjust the pH to 7.0 with 5 N NaOH. Autoclave. Pour into Petri dishes (~25 mL per 100-mm plate).