  Single-molecule tracking is a powerful way to look at the dynamic
organization of plasma membranes. However, there are some limitations to its
use. For example, it was recently observed, using numerical simulation, that
time-averaging effects inherent to the exposure time of detectors are likely to
bias the apparent motion of molecules confined in microdomains. Here, we solve
this apparently limiting issue analytically. We explore this phenomenon by
calculating its effects on the observed diffusion coefficients and domain
sizes. We demonstrate that the real parameters can be easily recovered from the
measured apparent ones. Interestingly, we find that single-molecule tracking
can be used to explore events occurring at a timescale smaller than the
exposure time.
