Labeling is typically performed by replacing specific atoms in the reactant molecules with their isotopic counterparts. For example: - Hydrogen-Deuterium Exchange: Involves replacing hydrogen atoms with deuterium in the reactant molecules. - Carbon-13 Labeling: Using carbon-13 instead of the more common carbon-12 in organic molecules. These labeled compounds are then subjected to the catalytic process, and advanced analytical techniques like NMR spectroscopy or mass spectrometry are used to monitor the progression of the labeled atoms.
