Latex spheres as markers for studies of cell surface receptors by scanning electron microscopy

Abstract

THE distribution of antigens and carbohydrate residues on the surfaces of cells, notably erythrocytes and lymphocytes, can be determined by binding antibodies or lectins to such macromolecules as ferritin^1,2, haemocyanin^3,4 or peroxidase^2,5, which serve as markers for transmission electron microscopy. Improved techniques in high resolution scanning electron microscopy (SEM), however, make it possible to determine the topographical distribution of molecular receptors on the surfaces of cells and tissues by similar histochemical techniques involving markers resolvable by SEM. LoBuglio et al.⁶ used commercial polystyrene latex particles, 2,300Å in diameter, as immunological markers for SEM work. But applications of this reagent are limited because the hydrophobic surface of the particles makes them stick non-specifically to many surfaces and molecules.