Molecular Individualism

Abstract

P. G. de Gennes How flexible are polymers? Most attempts to answer this question have involved average or aggregate measurements of many polymer chains. In his Perspective, de Gennes discusses results published in the same issue by Perkins et al. in which the flexibility of individual polymer strands has been measured. By tagging DNA strands with fluorescent markers, each chain could be observed in detail as it was stretched. A variety of different conformations were observed, and as de Gennes notes, two chains can exhibit very different behavior even when put under the same conditions of stretching. Understanding how polymers possess flexibility may be important in creating new materials.