Distinction Between Native and Denatured DNA by Means of Compression

Native and denatured DNA show different behavior on a compression mercury drop electrode in voltammetric and chronoamperometric measurements. The effect of both forms of adsorbed DNA on cyclic voltammetry of Cd2+ ions were followed in course of the growth, compression and repeated growth of the mercury electrode. The measurements have indicated different compression -expansion properties of the two DNA forms and possibilities of their voltammetric distinction in course of tens of seconds up to a few minutes. Different behavior was also observed on compression i–t curves after DNA accumulation on slowly growing or stationary mercury drop electrode. Most marked differences between i–t curves were observed in the potential region around –0.6 V (vs. SCE) where DNA is strongly adsorbed.