Thermodynamic aspects of some radioassays.

In a number of radioimmunoassays and radiotransin assays, effective equilibrium constants have been measured at different temperatures in order to define the relative contribution of changes of entropy and enthalpy to the change in free binding energy. In systems with a large enthalpy component, the lowest possible incubation temperature maximizes sensitivity, and control of temperature throughout the assay is important. Conversely, when enthalpy change is small, a high temperature allows rapid attainment of equilibrium without loss of sensitivity. At a theoretical level, the thermodynamic characteristics of binding may allow some insight into the nature of the binding process.