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 inter-molecular 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.