In the concentration range near the dimer/monomer equilibrium constant, one expects to observe a polarization intermediate between that associated with either dimer or monomer.  One can relate the observed polarization to the fraction of dimer or monomer using the additivity of polarizations first described by Weber (1952) namely:

where <P> is the observed polarization, fi is the fractional intensity contributed by the ith component and Pi is the polarization of the ith component.  One must then relate the fractional intensity contributions to molar quantities which means that one must take into account any change in the quantum yield of the fluorophore associated with either species.

The anisotropy function is directly additive (owing to the fact that the denominator  represents the total emitted intensity) and hence:

Polarization in Protein II