The Thermo Q-Exactive Orbitrap is a high resolution mass spectrometer suitable for accurate mass measurement as well as MS/MS studies. It is capable of ionization using conventional heated electrospray (HESI), atmospheric pressure chemical ionization (APCI), and nano-flow electrospray (Nano-ESI). Samples can be introduced directly via syringe infusion, or via one of two accompanying HPLC systems. For general applications, an ultra-high pressure HPLC is coupled with the Orbitrap to provide separation and UV data. For more specialized applications (fractionation, sample limited scenarios, 2D chromatography) a Nano-HPLC is available.