Direct measurement of cell adhesiveness by atomic force microscopy

Atomic force microscopy (AFM) has been used to detect molecular level biological forces. Because of its high spatial and time resolution, AFM could potentially overcome the limitations of conventional cell adhesion experiments. Using human fibrosarcoma cells and either fibronectin (FN) coated or bovine serum albumin (BSA) coated AFM cantilevers, we tested whether AFM could reliably detect adhesive forces between the surfaces of the cells and the AFM probes. In addition we examined the changes in adhesiveness after receptor blockade on a single cell. Our study revealed that AFM successfully detected differences in the cell-cantilever interactions between the FN and the BSA coated tips. Also, we observed that treating the cells with the amino sequence GRGDS reduced the interactions approximately 35% in 30 min compared to the pre-blocked condition.