Making LB Agar Plates

SOP

• SOP- Autoclave

Materials

• Petri Dishes
• Bacto Agar (BD 214010)
• LB Broth (Sigma L3522)
• Antibiotic, usually at 1000X, add 1 uL/mL of media

Protocol

• 500 mL makes about one sleeve of petri dishes
• Add 25g LB Broth per Liter to an appropriately sized beaker
• Add Water and Stir until clumps are gone
• Add 15 g Agar per Liter , this will not dissolve
• Transfer to a erlenmeyer flask at least 2x the volume that you are making
• Autoclave for at least a 20 minute liquid cycle
• Once the liquid is cool to the touch (dosent burn your hand to hold) add antibiotic and mix by swirling
• Pour into plates, covering the surface and avoiding bubbles
• Burn off bubbles with bunsen burner or pop with a sterile tip
• Let plates cool with the lids ajar
• Invert plates, place in sleeve and mark sleeve as LB/Amp or LB/Km depending on the antibiotic