Question

How is the melting curve of duplex DNA affected by decreasing the ionic strength of the solution?

Short answer

The T_m value of the melting curve of duplex DNA decreases as the ionic strength of the solution decreases.

Step-by-step solution

The melting curve of DNA.

The denaturation features of DNA are shown by the melting curve of DNA, which is based on nabsorption at a particular wavelength. Melting temperature,T_m, is the specific heatat which halves of the DNA are denatured.

The effect of the melting curve of duplex DNA.

The electrons of phosphate groups are much more exposed to one other at lower ionic strength. As a result, they reject each other even more. Phosphate group repulsion destabilizes the double helix, lowering the melting curve of duplex DNA.

Hence, the T_m value of the melting curve of duplex DNA decreases as the ionic strength of the solution decreases.