Direct measurement of single soft lipid nanotubes: nanoscale information extracted in a noninvasive manner.

We investigated the dynamics of single soft nanotubes of phospholipids to extract nanoscale information such as the size of the tube, which were several tens to hundreds of nanometers thick. The dynamic properties of the tubes obtained from direct observation by fluorescent microscopy, such as their persistence length, enable us to access the nanoscale characteristics through a simple elastic model of the membrane. The present methodology should be applicable to the nanosized membrane structure in living cells.