I began my research career as a theorist, pioneering computational studies of knots and links in circular DNA. My next important topic was DNA melting, were I discovered computationally the fine structure of the melting curves. For many years I worked for conformational properties of supercoiled DNA. In particular, I designed statistical mechanical models and computational methods to predict the appearance of alternative structures in supercoiled DNA. Later I ran a research lab at New York University where my main interests were related to DNA topology and supercoiling, DNA topoisomerases, and to the physics of DNA bending.

After closing my lab in 2011 I work as a freelance science writer.