ABSTRACT
This chapter describes methods for mechanically mapping the presence of particular proteins on cell membranes using the force mode of the atomic force microscope (AFM). To determine the sensitivity of the colloidal probe method of mapping cell surface proteins, M. Kim et al first estimated the density of specific molecules over a glass surface. AFM-based protein mapping has been applied in different laboratories to a wide variety of cells. P. Hinterdorfer et al. developed a new method of imaging by AFM, named “recognition imaging”, based on a specific interactions between the ligand immobilized on an AFM probe and specific receptors on solid or biological surfaces. Transferrin is a serum protein with the maximum capacity to bind or unbind two ferric ions and deliver them from the liver to the peripheral tissue cells. The conformation of transferrin is altered under the condition, and ferric ions are released although the transferrin–receptor complex remains intact.
