Molecular Probes Qdot nanocrystal conjugated primary antibodies are available for use in multicolor flow cytometry. They allow cell biologists to use an array of distinct colors to track multiple parameters within a single experiment. Click-iT Glycoprotein Profiling Reagents provide selectivity, sensitivity, and versatility in glycoprotein characterization, which overcomes the limitations of existing lectin-based or antibody-based techniques. The methodology first involves a labeling step, in which a very small bio-orthogonal moiety, or handle, is either metabolically or enzymatically incorporated into the glycan structure. Next in the detection step, a fluorescent label or biotin is selectively attached to the modified glycoprotein, a reaction typically completed in less than an hour. This simple, two-step procedure is efficient and produces a stable covalent bond, one capable of surviving mass spectrometry ionization and compatible with multiplexed proteomics applications using 1- or 2D gel electrophoresis or Western blot analysis to detect total proteins, total glycoproteins or total phosphoproteins simultaneously with the labeled glycoproteins.