An antibiotic (erythromycin) used during a conjugation experiment is stored as a stock solution of 5 mg/ml. You are pouring plates from a 500 ml flask of molten agar and need an antibiotic concentration of 100 μg/ml in the plates. How many μl of the antibiotic stock need to be added to the agar to get the desired concentration?
μl need to be added
