Selection of Lectin-Resistant Mutants of Animal Cells

This chapter describes a general approach, which proves to be highly successful, at isolating one family of mutants–those that express altered carbohydrate at the cell surface. Selection of a wide range of such mutants is possible by the availability of a large number of different lectins. Lectins are proteins or glycoproteins of nonimmune origin that specifically recognize certain sugar conformations. Lectin-resistant mutants are selected from a number of cell lines that exhibit very different growth properties from Chinese hamster ovary (CHO) cells—for example, mouse lymphoma cells that grow only in suspension. Cells that grow only in suspension cannot be plated in liquid medium to form colonies, and therefore, survival curves and P-tests cannot be generated by calculating relative plating efficiencies or by comparing confluency of monolayers. While cells that grow only in monolayer can more easily be pursued by the methods described for CHO cells.