The unzipping experiments provide direct measurements of the free energies ( ) and the salt corrections () at K for all the NNBP motifs ( ), but no information about the enthalpy ( ) and the entropy ( ) is provided. In order to infer these two magnitudes, we should perform more unzipping experiments at different temperatures an apply Eq. 3.5. At present this cannot be achieved with the minitweezers experimental setup because the temperature cannot be controlled at will. The changes in temperature dramatically affect the optics of the instrument, which introduces undesirable drift effects that compromise the resolution of the experiment.
However, combining the results from unzipping experiments with the measurements of melting temperatures of several oligos obtained by optical melting experiments  we can infer the enthalpies and the entropies. In order to do so, we define an error function that accounts for the mean squared error between the experimental melting temperatures  ( ) and the predicted ( ) ones for different oligos and salt conditions,
The error function (Eq. 5.4) is minimized with respect to the 10 enthalpies using a steepest descent algorithm that rapidly converges to the same solution when starting from different initial conditions. Table 5.3 contains the best fit values for the enthalpies and the entropies which are compatible with the UO values. Appendix M describes how the error of the fitting parameters was estimated.
JM Huguet 2014-02-12