Single-molecule techniques can provide insight into molecular interactions, reaction mechanisms, and structural stability. Limited throughput, complex instrumentation, and high cost have hindered accessibility of these techniques outside of specialized single-molecule labs. The Centrifuge Force Microscope (CFM) is one of the latest additions to this field, and aims to reduce the cost and complexity of single-molecule instrumentation. CFM uses the centrifugal force generated by a benchtop centrifuge to create tension on biopolymers like DNA while observing the force-induced changes happening to the molecules in real-time. In our newly published article, we expand the CFM concept and implementation to improve performance and accessibility for other labs.

The cover image for the December 1 issue of Biophysical Journal is an artistic illustration of the working principle of CFM, inspired by the idea of spinning carnival rides, such as the swing ride, the rotor ride, and the carousel. Here the basic concepts of the CFM are developed as a carnival swing ride, drawn from scratch in CorelDRAW based on photos of carnival rides. As the carousel (centrifuge) spins, the spheres (beads) connected through a tether (DNA) will be pulled away with a centrifugal force proportional to the square of the angular velocity of the spin and the mass of the beads. Unlike the carnival ride version, in reality the CFM is used to measure force-dependent dissociation kinetics of DNA, which means that the beads ultimately detach from their tethers. This system is suitable for other types of force-clamp studies such as force-dependent enzyme activity and molecular motor activity.

Additional details and research stories are available at https://www.halvorsenlab.com.

- Jibin Abraham Punnoose, Andrew Hayden, Lifeng Zhou, Ken Halvorsen