red fluorescent DNA staining

[Jos]

Dear reader,

Currently I am examining  living cells with Green Fluorescent Protein
and I want to combine this with a red fluorescent dye to visualize DNA
in vital cells using confocal laser scanning microscopy. I cannot use
Hoechst or other dyes with UV excitation, since cells will be damaged
and since our laser cannot excite Hoechst. Does anyone know of a vital
red fluorescent DNA dye with absorption spectrum around 567 nm and
emission above 600 nm? I already tried several dyes from Molecular
Probes (Syto-17 and Syto-64) but they appear to stain no nuclear DNA in
living eukaryotic cells.

Thank you very much for your reply.
Jos Broers