Description:We performed targeted metabolomic analysis on the Spemann-Mangold Organizer (SMO) tissue in the frog (Xenopus laevis) and the remainder of dissected embryos (RE). The goal of this study is to quantify a panel of targeted metabolite intermediates from glycolysis, phosphate energy pool, and mitochondrial activity including the TCA cycle. Metabolites were extracted from the dissected tissues, reconstituted, and analyzed using liquid chromatography (LC) electrospray ionization (ESI) mass spectrometry (MS). The targeted metabolite measurements were performed on a trapped ion mobility time-of-flight mass spectrometer (timsTOF PRO, Bruker). Targeted MS assays on the metabolite intermediates produced downstream, complemented by classical fluorescence-based metabolite assays when available, revealed local oxidative stress and enrichment of reactive oxygen species (ROS) in the SMO.