The aim of present study is to investigate the damage to salmon sperm DNA caused by Ni2+ and Co2+ ions and how they interact with Cu2+ and Mg2+ ions using fluorescent spectrometry. The results reveal that both Ni2+ and Co2+ ions damage salmon sperm DNA due to the binding of Ni2+ and Co2+ ions with DNA double strand. We can observe that the fluorescent intensity of DNA turns stronger and the corresponding wavelength becomes longer suggesting that the hypereffect and bathochromic shift occurred, both of which can be regarded as symbols of DNA denaturing. Compared to that observed in the DNA‐Ni2+/Co2+ complex, Cu2+ and Mg2+ ions have a less damage to DNA. The ability of Ni2+ or Co2+ ions binding to DNA will be inhibited by Cu2+ and Mg2+ ions, respectively, as they will compete for the binding site in the double strand, which can be proved by the decreasing of fluorescent intensity and the wavelength of DNA‐ Ni2+ or DNA‐Co2+ complex in the presence of Cu2+ and Mg2+ ions.
Thanks to the Halobios laboratory for Jiangsu province (2005HS008), funding from for Huai Hai Institute of Technology (KK01062).