ABSTRACT
The use of glycoconjugates in order i) to characterize endogenous lectins, ii) to study their intracellular localization and motion and iii) to help drugs, oligonucleotides and genes to be selectively taken up by animal cells, is based on the discovery of G.Ashwell, A.Morell and their coworkers (see Ashwell and Morell, 1974 for a review) at the end of the sixties. These authors showed that animal cells express sugar-binding proteins (lectins) on their surface and that these lectins very efficiently induce the endocytosis of their ligands (see Ashwell and Harford, 1982 for a review). Since, lectins have been found to be expressed both at the surface and inside a very large number of normal as well as transformed animal cells.
