Shear Rate Dependent Viscosity of Concentrated Protein Solutions

We have previously demonstrated the sensitivity of the low shear limiting viscosity to changes in protein pair interactions induced by varying buffer composition.  However, characterizing concentrated protein solutions with only a single viscosity value is incomplete.  A thorough analysis must include an evaluation of the shear rate dependence to identify the onset and extent of non-Newtonian behavior.  Therefore, rate sweeps were performed on a subset of the concentrated Bovine γ-Globulin formulations with a range of low shear plateau values to assess the impact of the protein-protein interactions (PPI) on the full viscosity profile.