Live Cell Ion Imaging
Imaging Workbench 6 is a powerful tool for monitoring and measuring
fast and slow time-lapse events, including ion concentration changes,
molecular interactions, cell growth and differentiation, and other
dynamic changes.
(1) Ion imaging
Imaging Workbench 6 can measure ion concentration change in live cells.
With appropriate fluorescent dyes, Imaging Workbench 6 can measure
the changes in free Ca2+, Mg2+, Zn2+, Na+, K+, H+ et al. Relative
concentration changes can be measured using non-ratiometric dyes,
and absolute values can be measured using ratiometric dyes. Imaging Workbench 6 supports multi-dye, multi-channel ratiometric or nonratiometric
imaging and can simultaneously control excitation and emission wavelength
for each dye-set. These make Imaging Workbench 6 the realistic choice
for multi-fluorescence or combined multi phase fluorescence imaging
for live cell research.
Imaging Workbench 6 is equally suitable for ratiometric measurements
using excitationor emission-shifting dyes. For example, the Ca2+ indicator
indo-1 shifts its fluorescence emission maximum from 485 nm towards
410 nm in the presence of free Ca, while the excitation maximum remains
at around 350 nm. Imaging Workbench 6 can control the emission wavelength
and image fluorescence at the two wavelengths when indo-1 is used.
(2) Ion imaging in GFP labeled cells
The availability of cellular markers tagged with the green fluorescent
protein (GFP) has recently allowed a large number of cell biological
studies to be carried out in live cells, thereby addressing the dynamic
organization of cellular structures. GFP is commonly used to label
transfected cells. As the transfection rate is usually not 100%, imaging
with GFP can help to successfully select transfected cells, and to
measure ion concentration of selected cells using fluorescent dyes.
and
Electrophysio-