Conversely, it appeared
that increasing cellular Zn2+ levels could prevent DNA
fragmentation upon pharmacological induction of apoptosis.
While these probes permitted visualization of cellular pools of
labile Zn2+ in living cells, they were hampered by their UVrange
excitation wavelength, which leads to photodamage and
high background fluorescence in the cell. Recent work from the
Petering lab has demonstrated that these probes form ternary
complexes with Zn2+-containing proteins.135 Thus, it appears
that instead of imaging the free or labile pool of Zn2+ within
cells, these probes actually image part of the Zn2+ proteome