Phospholipids in cpoA mutants. Lipids were extracted and separated by two dimensional TLC. 1.D and 2.D: first and second dimension (first dimension: CHCl3/MeOH/H20 = 65:25:4; second dimension: CHCl3/AcOH/MeOH/H20 = 80:14:10:3). Phospholipids were visualized by spraying with Molybdenum Blue spray reagent. PG: phosphatidylgylcerol; CL: cardiolipin. Spots were assigned according to the phosphatidylglycerol standard (see Additional file 1: Figure S1) and Fischer .