Figure 2.

Increasing concentrations of CT-DNA were present while the ligand (HL) and its complexes (1a-2a) were measured for their absorption spectra in a Tris-HCl buffer solution at 25°C. Arrows depict the changes in absorbance that occur as CT-DNA concentration is increased, and another arrow with isosbestic points denotes that equilibrium between DNA and complexes has been achieved.