Prepare Nutrient Agar (M112). Dispense 100 ml portions into 170 ml bottles. Autoclave 15 min at 121°C. Cool to 48°C.
Suspend 0.5 g L-tyrosine in 10 ml distilled water in 20 × 150 mm culture tube. Mix thoroughly with Vortex mixer. Autoclave 15 min at 121°C.
Combine 100 ml base with sterile tyrosine suspension. Mix thoroughly by gently inverting bottle 2 or 3 times. Aseptically dispense 3.5 ml into 13 × 100 mm tubes with frequent mixing. Slant tubes and cool rapidly to prevent separation of tyrosine.
Hypertext Source: Bacteriological Analytical Manual, 8th Edition, Revision A, 1998.