Scanning angle interference microscopy reveals cell dynamics at the nanoscale

Emerging questions in cell biology necessitate nanometer-scale imaging in live cells. Here we present scanning angle interference microscopy, capable of localizing fluorescent objects with nanometer-scale precision along the optical axis in motile cellular structures. We use this approach to resolve nano-topographical features of the cell membrane and cytoskeleton, as well as the temporal evolution, three-dimensional architecture, and nano-scale dynamics of focal adhesion complexes. Despite recent advances in super-resolution methodologies, real-time imaging with nano-scale precision remains challenging, especially along the optical axis. Current techniques (reviewed in1) have revealed the architecture of molecular complexes such as focal adhesions with unprecedented detail in fixed cells, yet the dynamic behavior of these structures remains largely unknown2. A need still exists for imaging methodologies capable of recording nano-scale structural details and movements in living cells as occurs during processes such as motility, where nano-scale dynamics of molecules are presumably coordinated across large spatial regions of the cell3-5