Inoculate duplicate Bacara or MYP agar plates with each dilution of sample (including 1:10) by spreading 0.1 mL evenly onto surface of each plate with sterile glass spreading rod. Incubate plates 18-24 h at 30°C and observe for colonies surrounded by precipitate zone, which indicates that lecithinase is produced. B. cereus colonies are usually a pink-orange color on Bacara or pink on MYP and may become more intense after additional incubation (see Fig. 1).