  Cell membranes separate the cell interior from the external environment. They
are constituted by a variety of lipids; their composition determines the
dynamics of membrane proteins and affects the ability of the cells to adapt.
Even though the study of model membranes allows to understand the interactions
among lipids and the overall mechanics, little is known about these properties
in native membranes. To combine topology and nanomechanics analysis of native
membranes, I designed a method to investigate the plasma membranes isolated
from a variety of single cells. Five cell types were chosen and tested,
revealing 20\% variation in membrane thickness. I probed the resistance of the
isolated membranes to indent, finding their line tension and spreading
pressure. These results show that membranes isolated from neurons are stiffer
and less diffusive than brain cancer cell membranes. This method gives direct
quantitative insights on the mechanics of native cell membranes.
