Synthesis and spectral properties of thiazole orange compounds as DNA fluorescent probes

The thiazole orange fluorescent dyes 4a,4b and 5 were synthesized and characterized for analysis of nucleic acid.Dye 4a was novel,and no previous paper had reported about it.Maximum of absorption spectra of the three dyes in Tris-HCl(pH = 7.0) was at about 504nm、502nm、507nm respectively.Fluorescent spectra of dyes together with ds-DNA showed that the dyes showed no fluorescence in Tris-HCl(pH = 7.0).Addition of the ds-DNA enhanced the fluorescence of the dyes with a good linear correlation between the fluorescent intensity of dye and the volume of ds-DNA.The modifying of the substitutes for dye 4a showed that dye 4a performed better fluorescent intensity.