C. difficile CD630 was grown overnight as described above in 10 mL cultures containing 10 μCi [1-14C] acetate (60 mCi/mol, PerkinElmer Life Sciences, Waltham, MA). The lipids were extracted, carrier lipids fromthe same specieswere added and ~10,000 cpmof the radioactively labeled lipids was separated by 2D-TLC as described above. Radiolabeled lipids were visualized and quantified with Typhoon 9410 phosphorimager (Amersham Biosciences, Arlington Heights, IL), equipped with Image-Quant software.