The energy used or expended in an equilibrium binding reaction is described by the equation,

ΔG^{o} = ΔH^{o} –TΔS^{o}

where G^{o} is the Gibbs Free Energy, H^{o} is enthalpy, T is the absolute temperature (in ^{o}K), and S^{o} is entropy.

The change in Gibbs Free Energy, ΔG^{o}, is related to the dissociation constant for binding, K_{D}, by the equation,

ΔG^{o} = RT ln K_{D},

where R is the gas constant [1.98722 cal/^{o}K•mol], and T is the absolute temperature.

Biacore^{®} instrument measurements of K_{D} as a function of temperature, T, can therefore reveal the enthalpy and entropy of any binding reaction, from the following relationship:

ln K_{D} = ΔH^{o}/RT – ΔS^{o}/R

Thus, measuring K_{D} as a function of T yields information about the thermodynamics of the binding reaction.