Tryptic Soy Agar (TSA)

• 1. Add 40 g of TSA powder (BD 236950) to a final volume of 1 L of H₂O, stir well to mix, and autoclave for 15 min at 121°C under standard conditions.

• 2. (Optional) Once cooled to ∼50°C, add (if required) the necessary antibiotics to the desired concentration from a 100×–1000× stock solution.

• 3. Using sterile technique, pour ∼20–25 mL of medium into 90-mm-round Petri dishes. Let the plates solidify, turn them lid side down, and let them dry overnight at room temperature before use.

• 4. Store plates without antibiotics for up to a few months at 4°C. Store plates with antibiotics for up to 1 mo at 4°C.

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