The atomic force microscope (AFM) is being utilized in even more clever ways to reveal details of molecular structure and function. As an example, Julio Fernandez and Hongbin Li have used the AFM in the force-clamp mode to monitor the folding trajectory of a single protein. They have demonstrated in a unique way in which a single protein behaves when put under tension, and then what happens when the tension is relieved.

Fernandez and Li linked several molecules of ubiquitin, a small protein, together to form a polyubiquitin chain. With one end of the chain attached to a substrate, the tip of a soft cantilever of the AFM attached to a single protein, and from one to nine ubiquitin molecules were picked up.