Our lab uses biophysical methods, with particular emphasis on micromanipulation of single DNA molecules and single chromosomes, to study the internal structure of chromosomes in vivo, and to study chromosome-organizing proteins and DNA topoisomerases in vitro. We also develop mathematical models relevant to these types of experiments. Projects in progress involve combining fluorescence microscopy and force microscopy in experiments on DNA-protein complexes and whole chromosomes, and in-vivo studies of coupling of chromosome dynamics to gene expression.