Metabolic radiolabeling of animal cell glycoconjugates

This unit describes metabolic labeling techniques that provide specific information about the structure, sequence, and distribution of the sugar chains of glycoconjugates. In the Basic Protocol, cells in culture are grown through several population doublings in complete medium supplemented with radiolabeled glycoconjugate precursors to reach a steady-state level of incorporation. In the alternate protocols, cells are cultured for a short period of time in a deficient medium that contains a high concentration of radiolabeled precursor. A pulse or pulse-chase labeling procedure is provided to analyze precursor-product relationships. With the sequential pulse-labeling method described here, it is possible to obtain quantities of labeled glycoconjugates with the use of a minimum amount of labeled precursor by using the same batch of medium to pulse-label a series of cultures. A support protocol describes the preparation of multiply deficient medium (MDM) for use in making appropriate deficient media.