MANIPULATION OF INDIVIDUAL VIRUSES - FRICTION AND MECHANICAL-PROPERTIES

We present our results on the manipulation of individual viruses using an advanced interface for atomic force microscopes (AFMs), We show th at the viruses can be dissected, rotated, and translated with great fa cility. We interpret the behavior of tobacco mosaic virus with a mecha nical model that makes explicit the competition between sample-substra te lateral friction and the flexural rigidity of the manipulated objec t. The manipulation behavior of tobacco mosaic virus on graphite is sh own to be consistent with values of lateral friction observed on simil ar interfaces and the flexural rigidity expected for macromolecular as semblies. The ability to manipulate individual samples broadens the sc ope of possible studies by providing a means for positioning samples a t specific binding sites or predefined measuring devices. The mechanic al model provides a framework for interpreting quantitative measuremen ts of virus binding and mechanical properties and for understanding th e constraints on the successful, nondestructive AFM manipulation of de licate samples.