Development and validation of a nanometer manipulation and measurement system for biomechanical testing of single macro-molecules

A biomechanical testing system for single macro-molecules has been develope d using optical tweezers. To achieve nanometer manipulation and measurement , a piezo-stage and an interferometer were adopted. A systematic calibratio n was then performed on the displacement resolution. The piezo-stage has a noise level around 1 nm standard deviation, and the interferometer has a no ise level of less than 5 nm standard deviation. The results revealed that t he system has a nanometer resolution which is sufficient for the measuremen t of deformation and stiffness of single macro-molecules. (C) 1998 Elsevier Science Ltd. All rights reserved.