geoRge

geoRge is a software tool designed to analyze untargeted LC/MS data from stable isotope-labeling experiments. The tool is written in the open-source programming language R and runs on the output structure of the widely used XCMS package. It is capable of automated untargeted isotope annotation and relative quantification, which are essential processes for understanding the flow of chemical moieties through metabolic pathways.

Unlike other existing tools that use labeled samples to track stable isotopes, geoRge uses both labeled and unlabeled biologically equivalent samples to compare isotopic distributions in the mass spectra. This is possible because isotopically enriched compounds change their isotopic distribution compared to unlabeled compounds. The resulting differences are reflected in a number of new m/z peaks and higher intensity peaks in the mass spectra of labeled samples relative to the unlabeled equivalents.

GeoRge has been demonstrated to be effective in analyzing LC/MS data from a human retinal pigment epithelium cell line (ARPE-19) grown on normal and high glucose concentrations that mimic diabetic retinopathy conditions in vitro. This has been made possible through the automated untargeted isotope annotation and relative quantification capabilities of geoRge.

To ensure data traceability and reproducibility, raw LC/MS files have been deposited in MetaboLights (MTBLS213).