Liquid chromatography/mass spectrometry profiling analysis of lipid content. A LTQ Orbitrap XL instrument (Thermo Fisher Scientific San Jose, CA) was used for the analysis. It was coupled to an Agilent 1100 series LC (Agilent Technologies, Santa Clara, CA) equipped with a micro well plate auto sampler and binary pumping device. Reverse phase liquid chromatography was used to analyze the samples. An Agilent Eclipse XDB-C8 column with 2.16150 mm, 3.5 mm dimensions was used for the separation. Solvent A consisted of water +0.1% piperidine. Solvent B contained acetonitrile : methanol (50:50 v/v) +0.1% piperidine. The flow rate was 300 mL/minute. A volume of 10 mL was loaded onto the column. The gradient was as follows: time 0 minutes, 50% B; time 25 minutes, 95% B; time 45 minutes, 95% B; time 50 minutes, 50% B; time 60 minutes, 50% B. The MS analysis used negative polarity electrospray ionization. The source voltage was 4.0 kV, source current 100 mA, capillary voltage 230.0 V, tube lens voltage 2100.0 V. The capillary temperature was 200uC, sheath gas flow was 35, auxiliary and sweep gas were both set to 0. Data were acquired using data dependent scanning mode. FTMS resolution of 60,000 with a mass range of 70-1200 was used for full scan analysis and the ITMS was used for MS/MS data acquisition. The top three most intense ions were acquired with a minimum signal of 500, isolation width of 2, normalized collision energy of 35, default charge state of 1, activation Q of 0.250, and an activation time of 30.0. The samples were evaluated with Thermo XCalibur software (version 2.1.0) and downstream alignment done with an in-house data processing package called Omics Discovery Pipeline [63, 64] .