We investigated the dynamics of single soft nano-tubes of phospholipids to
extract nano-scale information such as size of tube, which are several tens to
hundreds of nano-meters thick. The scaling law of the nano-tube dynamics in
quasi-2-dimensional space was revealed to be constituent with that of a
polymer. The dynamic properties of the tubes obtained from direct observation
by fluorescent microscopy, such as their persistence length, enable us to
access the nano-scale characteristics through a simple elastic model of the
membrane. The present methodology should be applicable to the nano-sized
membrane structure in living cells.Comment: 5 pages (main manuscript), 2 pages (supplemental), 5 figure