DNA and RNA melting is fundamental to all the technologies of hybridization, PCR primer design, and RNA structure prediction. Melting curves are straightforward to simulate if we are content with two-state transitions, where any single molecule is fully single stranded or fully double stranded. Here is a PDF file with some of the math needed to model the melting process. More intuitive is an Excel spreadsheet which allows you to enter thermodynamic values and predict the melting curve. Enjoy. Specifically:

1. Change the values of enthalpy and entropy and see how the curve shifts.
2. Use the relationship ΔG₃₇ = ΔH-310ΔS to change both enthalpy and entropy but keep ΔG₃₇ nearly constant. How does the shape of the curve change? Try making both large (+/- 40 %) and small (+/- 5 %) changes.
3. Based on the results from question 2, qualitatively estimate how precisely ΔH°, ΔS°, ΔG°₃₇ and T_M could be measured from experimental data, or at least order the parameters according to which ones can be most to least precisely estimated.

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