Making LB Agar Plates

SOP

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