Validation of DOMS with conventional total lipid extracts. Representative TAG profiles from total lipid extracts of purified LDs from mature cotton embryos of Coker 312 wild type (a) and Bnfad2 transgenic (b) lines. Dominant TAG species are identified as ammonium adducts [M + NH4]+ with peaks labeled according to the total number of carbons followed by the total number of double bonds for that particular TAG mass-to-charge ratio. Quantitative comparison of molecular TAG content (c, Coker 312; d, Bnfad2) acquired through direct organelle mass spectrometry of small LD populations (10–25 LDs) relative to conventional total lipid extracts. Predominant acyl chain combinations were quantified by integrating the absolute intensities of peaks identified through tandem MS, correcting for isotopic overlap, and converting to molecular percentages. P, 16:0-palmitic acid; O, 18:1-oleic acid; L, 18:2-linoleic acid.