2.13 Filipin cholesterol staining
Cells grown on glass coverslips were fixed with 4% PFA and then stained
with 5 μg/ml filipin-III (Cayman, USA) in PBS containing 1% FBS for 2 h
to examine intracellular distribution of free cholesterol. The stained
cells were observed under a LSM 700 confocal microscope (Carl Zeiss,
Germany). Signal intensities of plasma membrane were quantified using
Image J software
(http://imagej.nih.gov/ij/).