Analysis of sterol metabolites by TLC. R. equi USA-18 (WT) or R. equi USA-18ΔB8 (ΔB8) was cultivated in 0.2% cholesterol (Cho) or phytosterol (Phy) containing medium at 37°C, 200 rpm. Tween 20 (Tw20) or Tween 80 (Tw80) was included in the medium for sterol solubilization. The broth was harvested, at the indicated time, and extracted with ethyl acetate. The dissolved compounds were analyzed by TLC as described in Materials and methods. Cholesterol, AD, and ADD were used as standards.