 we report a novel method for the measurement of lipid 
 nanotube 
 radii . 
 membrane translocation is monitored between two nanotube - connected 
 vesicles , during the expansion of a receiving vesicle , by observing 
 a photobleached region of the nanotube . 
 we elucidate nanotube radii , 
 extracted from spe vesicles , enabling quantification of membrane composition 
 and lamellarity . 
 variances of nanotube radii were measured , showing 
 a growth of 4056 nm , upon increasing cholesterol content from 
 0 to 20% . 
Supplementary Material