Thermal stability of DNA interacting with furazolidone and Cu(II) ions.

Furazolidone, on complexing with DNA, led to its thermal stabilization. The increase in transition temperature of DNA (delta Tm) increased linearly with % A--T content. Increasing concentration of Cu(II) ions progressively lowered the transition temperature of DNA, but Cu(II) ions were not equally effective in lowering the transition temperature of furazolidone-DNA complex. When equimolar amounts of Cu(II) ions and furazolidone were used, the stabilisation effects of furazolidone prevailed over the destabilisation effect of Cu(II) ions.