  Spatial Fluorescence Cross Correlation Spectroscopy is a rarely investigated
version of Fluorescence Correlation Spectroscopy, in which the fluorescence
signals from different observation volumes are cross-correlated. In the
reported experiments, two observation volumes, typically shifted by a few
$\mu$m, are produced, with a Spatial Light Modulator and two adjustable
pinholes. We illustrated the feasibility and potentiality of this technique by:
i) measuring molecular flows, in the range 0.2 - 1.5 $\mu$m/ms, of so-lutions
seeded with fluorescent nanobeads or rhodamine molecules (simulating active
transport phenomenons); ii) investigating the permeability of the
phospholipidic membrane of Giant Unilamellar Vesicles versus hydrophilic or
hydrophobic molecules (in that case the laser spots were set on both sides of
the membrane). Theoretical descriptions are proposed together with a
discus-sion about Fluorescence Correlation Spectroscopy based, alternative
methods.
