Figure 3.

IAA alters the DNA structure. (A) UV absorption spectra of IAA (25 μM) with increasing amounts of pBlueScript (pBS) plasmid. Appropriate mixtures of ethanol buffer and pBS plasmid were used as reference and subtracted from each measurement. (B) UV-Vis absorbance spectra of ethidium bromide (EtBr) (7 μM) in absence (black line) and presence (blue line) of calf thymus DNA (ctDNA). The absorption spectra of the EtBr–ctDNA complex in the presence of increasing concentrations of IAA (2, 10, 15, 25 mM) were also reported. (C) Circular dichroism spectra of ctDNA (125 ng mL⁻¹) in the presence of increasing concentrations of IAA.