  In the past decades, advances in microscopy have made it possible to study
the dynamics of individual biomolecules in vitro and resolve intramolecular
kinetics that would otherwise be hidden in ensemble averages. More recently,
single-molecule methods have been used to image, localize and track
individually labeled macromolecules in the cytoplasm of living cells, allowing
investigations of intermolecular kinetics under physiologically relevant
conditions. In this review, we illuminate the particular advantages of
single-molecule techniques when studying kinetics in living cells and discuss
solutions to specific challenges associated with these methods.
