In the EB-DNA binding studies, we have noticed that the metal complexes can displace the intercalator EB from the DNA base pairs, as seen from the quenching of fluorescence of EB-DNA studies. However, the DNA binding constant of EB is known to be 1× 10^7 M-1, while for the complexes it is only of order 10^5 or 10^6 M-1. So, how can such a strong intercalator such as EB can be displaced by the metal complexes which has less binding efficacy towards DNA?