2-Deoxy-D-glucose is a glucose molecule which has the 2-hydroxyl group replaced hydrogen, so that it cannot undergo further glycolysis. Glucose hexokinase traps this substance in most cells (with exception of fiver and kidney) so that it makes a good marker for tissue glucose use and hexokinase activity. Many cancers have elevated glucose uptake and hexokinase levels. 2-Dexoyglucose labeled with tritium or carbon-14 has been a popular ligand for laboratory research in animal models, where distribution is assessed by tissue-slicing followed by autoradiography. Sometimes in tandem with either conventional or electron microscopy.