Mass spec instrumentation information
Metabolomics core laboratory consists of 6490/6495/ 6495B Agilent LC-QQQ mass spectrometry which is used for targeted metabolomics and metabolic flux and AB Sciex Triple tof 5600 system to measure unbiased lipidomics, 6550 Agilent LC- Q-TOF Mass Spectrometry for unbiased metabolomics.
Targeted Metabolomics serves all researchers at Baylor College of Medicine by providing services to perform quantitative measurements of known compounds through the use of high-pressure liquid chromatography and mass spectrometry. The established the below-listed methods by standard protocols and encourages the development of new protocols to quantity additional compounds.
To test mechanisms that are responsible for altered regulation of steady-state levels of metabolites, in the cell, measurements of metabolic flux through pathways is required. By providing 13C or 15N isotope labeled metabolic substrates (such as isotopic labeled glucose, glutamine, or lactate) to living cells, isotopomer patterns of key metabolites can be precisely measured using mass spectrometry. These analyses can provide valuable information on both pathway activities and metabolite pool sizes.
Since all metabolites are either reactants or products in metabolic pathways, changes in their levels due to either altered production or altered disposal are determined by the kinetic rates of key steps within those pathways. Services available currently use cell lines only and are confined to the targeted analysis of pathways as indicated below: (and view the Metabolic Flux Service page).
Glucose metabolic fluxCitric acid cycle (TCA cycle) metabolic fluxGlutamine FluxLipid or Fatty acid Metabolism.
Untargeted LC-MS Based Shotgun Lipidomics
Lipidomics approaches can provide valuable new insights into the role of lipid molecular species in human health and disease and may identify potential lipid biomarkers that can be developed for diagnostic/prognostic and therapeutic use. Our strategy is to use a ABSCIEX 5600 triple TOF MS that combines high-sensitivity detection, high resolution with the fast acquisition speeds, and stable mass accuracy over days of acquisition accompanied by RP-
UPLC methodology. Identification of lipids is accomplished by data-dependent product ion (MS/MS) information of human plasma, tissues, and urine lipid species in both positive and negative ionization modes. During the electrospray ionization, molecular ion adducts such as [M+H]+, [M+Na]+ and [M+NH4]+ or [M−H]−, and [M+CH3COO] − are formed in both positive and negative modes. Data-dependent MS/MS acquisition or MS/MS ALL acquisition provides information on the nature of the head group and/or neutral loss of the head group from the molecular ion adducts.
The information on fatty acids composition of the lipids is obtained in the negative mode. (View the Lipidomics service page.)