Immunostaining thin layer chromatograms TLC is a very sensitive detection technique of functionally active carbohydrate ligands of protein receptors. Carbohydrate structures are detected in glycolipids from complex mixtures of molecules extracted from the relevant target tissue. Proteins analyzed can be antibodies, chimeric Ig proteins, selectins, lectins, toxins, and other carbohydrate binding proteins. John L. Magnani~GlycoTech Corporation, Rockville, Maryland