ECIS
can be applied to follow the kinetics of cell spreading to the electrode
surface with a time resolution of only a few minutes or better. In the
experiment shown below we followed the attachment and spreading of initially
suspended MDCK-II cells to the surface of gold-film electrodes that were
pre-coated with four different proteins: Fibronectin (FN), Laminin (LAM),
Vitronectin (VN) or Bovine Serum Albumin (BSA).
The
time of course of cell spreading is monitored with highest sensitivity
by measuring the capacitance of the electrode above a threshold frequency
of appr. 10 kHz (here we used 40 kHz). Capacitance readings then mirror
the increasing surface coverage of the electrode and are linearly dependent
on the degree of cell spreading.
It
is possible to extract the time necessary for half-maximum cell spreading
t1/2 and an apparent
spreading rate s from the ECIS raw data. Spreading characteristics can
thus be described and compared in a highly quantitative fashion. |
