Abstract
The use of a functionalized tip to measure the force of the interaction between ligands and receptors by atomic force microscopy has been discussed for more than a decade, and single-molecule recognition using a functionalized tip from processed samples is achievable now. Techniques for detecting and characterizing specific individual molecules from a living cell are still developing and are discussed in this article. Because many diseases have their roots at the molecular scale and are best understood as a malfunctioning of biologic nanomachines, these techniques should find widespread use in basic biomedical research once the remaining barriers are overcome.