Year-end Sale % OFF 
Abstract
The interaction of azur A (AA) with DNA in aqueous medium has been studied by measurement of resonance light scattering (RLS), and accordingly a method for DNA determination is proposed with sensitivity at the ng level. At pH 3.29 and ionic strength 0.003, the RLS of AA was greatly enhanced by DNA characterized by the maximum scattering peaks at 398 and 472 nm. Mechanistic studies show that the interaction of AA with DNA involves the salting-out of AA encouraged by the electrostatic attraction of the positive charge of AA molecules with the negative charges of the DNA polyanion, and the salted-out AA molecules bind with DNA in a weak cooperative mode. Scatchard plots were constructed for the interaction equilibrium of AA with double-stranded DNA based on the RLS data, and it was found that each nucleotide residue could bind to four AA molecules with the binding constant being at the 10 5 level. The enhanced intensity of RLS is proportional to the concentration of calf thymus DNA and fish sperm DNA in the range 0–2.0 μg ml −1 if 3.0×10 −5 mol l −1 AA was employed. Four synthetic samples were determined satisfactorily.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
