Optical Tweezers (OT) is a single-molecule technique that allows manipulation and measurement of the mechanical properties of biomolecules in real time. It can be used to manipulate and stretch single DNA molecules between two beads with sub-nanometre and sub-picoNewton resolution. On top of that, we have available a hybrid system combining OT with confocal microscopy, which enables to manipulate single DNA molecules while simultaneously imaging the fluorescence between the beads in real time.
The system available in our group is the C-Trap™ from Lumicks. This equipment offers the combination of dual OT with confocal microscopy and a microfluidic device, all integrated in a single instrument, which facilitates a simple and fast workflow for bead 
What we obtain from our measurements are (i) kymographs that give unique insights into the dynamic interactions between proteins and substrates, such as DNA; (ii) force-extension curves that allow for correlating the protein activity and binding kinetics with the mechanical properties of the protein-substrate complex.
C-Trap-related papers of the group
Balaguer FA, Aicart-Ramos C, Fisher GL, de Bragança S, Martin-Cuevas EM, Pastrana CL, Dillingham MS*, Moreno-Herrero F*. Elife (2021)
CTP promotes efficient ParB-dependent DNA condensation by facilitating one-dimensional diffusion from parS.