Melting parameters of DNA complexes with several intercalators Biology

Abstract

Comparative study of DNA complexes with acridine orange (AO), ethidium bromide (EtBr) and methylene blue (MB) has been carried out at 0.02 M ionic strength of solution in 0<r 0.33, r= [ligand]/ [DNA] range. The values of changes of melting parameters ((1/Tm) and (T/Tm 2 )) of these complexes were determined. From the obtained data it was revealed that the dependence of (1/Tm) enhances in the whole interval of change of r for three ligands, while the dependence of (T/Tm 2 ) rises at relatively low values of r and comes out to plateau in the case of AO and MB; in the case of EtBr this dependence takes bell-like form.