and LipidTOX Red Neutral lipid stain was obtained from life technologies.
Huh-9-13 cells were seeded in glass bottom 35 mm culture dishes (Mattek)
at a density of 25.000 cells/dish in complete DMEM without G418 at
37 °C and 5% CO2. The next day medium was replaced
with complete DMEM containing either the proper dilution of the compound
to be tested or DMSO. The cells were further incubated for 3 days
at 37 °C and 5% CO2, after which the medium was replaced
with complete medium without neutral red and either Nile Red (2 μg/mL),
monodansylcadaverine (50 μM), or LipidTOX Red Neutral lipid
stain (diluted 1/1000). Next, the cells were incubated for an additional
30 min at 37 °C and 5% CO2 after which the cells were
imaged using a laser-scanning SP5 confocal microscope (Leica Microsystems)
equipped with a DMI 6000 microscope and an Acousto optical beam splitter.
For Nile Red the yellow-gold fluorescence was monitored at an excitation
wavelength (λex) of 552 nm and an emission wavelength
(λem) of 636 nm. The red fluorescence was monitored
at λex of 485 nm and λem of 525
nm. Monodansylcadaverine was imaged at λex of 340
nm and λem of 530 nm, and LipidTOX Red Neutral lipid
stain was assessed at λex of 577 nm and λem of 609 nm.