Division 3 Antibiotic medium

A typical example for cloacal swabs is: 10 000 units/ml penicillin, 10 mg/ml streptomycin, 0,25 mg/ml gentamycin and 5 000 units/ml mycostatin in phosphate buffered saline at pH 7,2 to 7,4. 50 μg/ml oxytetracycline may be added. The antibiotic concentrations can be reduced five-fold for tracheal swabs. It is imperative when making the medium that the pH is checked after the addition of the antibiotics and re-adjusted.