Optical tweezers stretching of chromatin.

Recently significant success has emerged from exciting research involving chromatin stretching using optical tweezers. These experiments, in which a single chromatin fibre is attached by one end to a micron-sized bead held in an optical trap and to a solid surface or second bead via the other end, allows manipulation and force detection at a single-molecule level. Through force-induced stretching of chromatin, mechanical properties, specific intermolecular bond strengths and DNA-protein association and dissociation kinetics have been determined. These studies will be extremely fruitful in terms of understanding the function of chromatin structure and its dynamics within the cell.