THE INTERACTION OF SAFRANINE-T WITH ANION IC SURFACTANT AND ITS APPLICATION IN LABELING DNA

The study of the properties of the visible spectra and fluorescent spe ctra of safranine T(ST) in the solution of anionic surfactants(AS) was reported. The results showed that ST formed complex with AS molecule when the concentration of AS was low, and the absorbance and fluoresce nce intensities of ST, therefore, decreased. A non-fluorescent dimeric dye was formed on the formation of premiceller aggregation of AS when the concentration of AS was made higher, and thus the fluorescence in tensity decreased dramatically, and a new peak in visible spectra appe ared, When the surfactant concentration was increased above the critic al micelle concentration(CMC), the dimeric dye dissociated, and a new fluophore with a high quantum yield was formed. The posibility of usin g the non-fluorescent dimeric dye as a fluorescent probe for deoxyribo nucleic acid was also studied. The dimeric dye showed a highly DNA bin ding constant and significant change of fluorescent behaviour was obse rved when the dimeric dye interacted with double strands DNA. It was o bvious that the dimeric dye may be used as a good DNA probe.