Boil to dissolve ingredients. Avoid overheating, which causes softening of agar and darkening of medium color. Autoclave 15 min at 121°C. Dispense 20-25 ml into sterile 15 x 100 mm petri dishes. Final pH, 5.5 ± 0.2.

For cosmetics use

Cool medium to 47-50°C after autoclaving. Dispense 4 ml stock filter-sterilized chlortetracycline HCl solution (1 g/100 ml) per liter of medium to yield final concentration of 40 ppm chlorotetracycline HCl. Mix thoroughly and dispense 20 ml portions into 15 x 100 mm petri dishes.

Hypertext updated by rim/cjm 2005-OCT-21