Single DNA molecule grafting and manipulation using a combined atomic force microscope and an optical tweezer

In this letter, we report on spatially selecting and grafting a DNA-tethered bead to an atomic force microscope (AFM) cantilever, using an optical tweezer. To quantify this technique, we measure force versus extension of a single DNA molecule using AFM. For such studies, we have developed a micromanipulation approach by combining an AFM, an optical tweezer, and visualization setup. The ability to select a single DNA polymer and specifically graft it to a localized position on a substrate opens up new possibilities in biosensors and bioelectronic devices. (C) 1997 American Institute of Physics. [S0003-6951(97)01051-6].