Best practice for improved accuracy: A critical reassessment of van't Hoff analysis of melt curves.

Biomolecular thermodynamics, particularly for DNA, are frequently determined via van't Hoff analysis of optically measured melt curves. Accurate and precise values of thermodynamic parameters are essential for the modeling of complex systems involving cooperative effects, such as RNA tertiary structure and DNA origami, because the uncertainties associated with each motif in a folding energy landscape can compound, significantly reducing the power of predictive models. We follow the sources of uncertainty as they propagate through a typical van't Hoff analysis to derive best practices for melt experiments and subsequent data analysis, assuming perfect signal baseline correction. With appropriately designed experiments and analysis, a van't Hoff approach can provide surprisingly high precision, e.g., enthalpies may be determined with a precision as low as 10-2 kJ ⋅ mol-1 for an 8-base DNA oligomer.