3-O-methyl-D-glucose, labeled on the methyl group with C-14. 3-O-methyl-D-glucose (OMG) is a glucose analog that is readily transported into most cells, but does not become phosphorylated and therefore will equilibrate across the cell membrane. Equilibrium is usually reached rapidly, so glucose uptake assays may only be linear for a short period of time; you may need to take your measurements fairly quickly. This analog cannot be further metabolized by cells.
