Scientists can use optical tweezers to trap beads, as depicted at the right, and catch a biomolecule, such as DNA, in between. This biomolecule can then be manipulated by moving the beads, while the force and extension are measured. Fluorescently labeled proteins can be visualized with confocal or STED fluorescence microscopy. The combination of optical tweezers with simultaneous multicolor fluorescence measurements allows correlating the mechanical properties of the DNA with the protein activity. With optical tweezers – fluorescence microscopy you can:
- Visualize and directly measure DNA-protein interactions in DNA organization to find the kinetics and exact mechanisms involved at the single-molecule level
- Correlate the mechanical properties of the DNA with the binding location and quantity of DNA organization proteins
- Measure the conformational changes which structures – such as nucleosomes or histones – undergo as they interact with DNA organization proteins
- Perform experiments under biologically relevant conditions and highly crowded environments and link the in vitro experiment with the in vivo situation
- Study the effect of small molecules and biologics in DNA organization pathways.