Qqq6490 mass spectrometer

Genomic DNA was enzymatically digested into single nucleosides by a mixture of DNase I, calf intestinal phosphatase, and snake venom phosphodiesterase I at 37 °C for 12 h. After the enzymes were removed by ultrafiltration, the digested DNA was subjected to UHPLC-MS/MS analysis. The UHPLC-MS/MS analysis was performed on an ultra-high-performance LC system coupled with a QQQ6490 mass spectrometer equipped with a jetstream electrospray ionization source (Agilent, Santa Clara, CA). A reverse-phase Zorbax SB-C18 column (2.1 × 50 mm, 1.8-μm particles) was used for UHPLC separation. The mass spectrometer was operated under positive ionization using multiple reactions monitoring (MRM) mode. All the quantification data are included in Table S15.

Please see the Supporting information (S1 File) for a complete description of lipidomics materials and methods. Lipids for LC-MS analysis were extracted using a modified Bligh Dyer extraction protocol. Lipids were analyzed using Agilent LC 1290 binary pump coupled with Ascentis Express RP amide (50 ×2.1 mm, 1.8u), and separated lipid species were detected using Agilent QQQ 6490 mass spectrometer, using multiple reaction monitoring (MRM) as previously published [6 (link)].
For GC-MS based fatty acid analysis, dried samples and dried fatty acid calibration mix were derivatised with 5 μL of Meth-Prep^™ II (Grace Davison Discovery). The samples were then analyzed on a GC-MS system comprised of a Gerstel 2.5.2 Autosampler, a 7890A Agilent gas chromatograph and a 5975C Agilent quadrupole mass spectrometer (Agilent, Santa Clara, USA) [18 , 19 (link)].