Sc. Benson et al., HETERODIMERIC DNA-BINDING DYES DESIGNED FOR ENERGY-TRANSFER - STABILITY AND APPLICATIONS OF THE DNA COMPLEXES, Nucleic acids research, 21(24), 1993, pp. 5720-5726
Spectroscopic studies of the complexes of double-stranded (ds) DNA wit
h the polymethylene-amine linked heterodimers thiazole orange-thiazole
blue, thiazole orange - ethidium, and fluorescein - ethidium, in each
case show efficient energy transfer from donor to acceptor chromophor
es (Benson,S.C., Singh,P. and Glazer,A.N. (1993) accompanying manuscri
pt). A quantitative assay of the stability of such complexes during ge
l electrophoresis is presented. The off-rate of dye from complexes for
med at an initial dsDNA bp:dye ratio greater-than-or-equal-to 10:1 fol
lows strict first-order kinetics. The t0.5 values for the dissociation
of a series of related dyes provide a quantitative criterion for the
design of DNA-binding fluorophores. Complexes of dsDNA with the monome
ric propidium and cyanine dyes, -diazanonyl)-3,8-diamino-6-phenyl-phen
anthridinium bromide trihydrobromide] and (N,N'-tetramethyl-1,3-propan
ediamino)propyl thiazole orange yl]-1-(4,4,8-trimethyl-4,8-diazanonyl)
-quinolinium diiodide], are much more stable than those with their wid
ely used counterparts, ethidium and thiazole orange. Applications of t
he new dyes in post-staining of gels and in the multiplex detection of
DNA restriction fragments are presented.