Figure 1.

Experimental setup of Cas12a binding and cleavage onto λ-DNA. (A) Schematic of the experimental assay (left) and the microfluidic chip (right). The RNP assembly of the target DNA includes the NT-strand (green), T-strand (grey), crRNA (red) and the location of the fluorescent probe. (B) Example of kymograph showing Cas12a binding (red channel) at 10 pN. A single-pixel line scan is made along the DNA axis and plotted over time. Intensity peaks indicate binding events. (C) Representative force-distance curves in the presence and absence of Mg²⁺. In the absence of Mg²⁺, the force increases with increasing inter-bead distance, while in the presence of Mg²⁺, the DNA tether ruptures at low forces, as marked by a sudden drop in force. The forward curves are black with some transparency and the backwards curves are red. Hysteresis is observed in some of the reverse curves.