Flow induced dispersion analysis is a capillary-based technology that enables absolute determination of a proteins hydrodynamic radius (RH) in solution and in complex media. This RH determination is possible over a wide dynamic range with regard to particle size (0.5-500nm) and binding affinity (pM - mM). We discuss how applying this to protein QC we can determine in a 5-minute assay, using as little as 40nl of protein, 8 different protein QC parameters. The technology enables absolute size determination, reveals and quantitates aggregation, can calculates a poly dispersity index, verifies oligomeric state and can be used to determine the degree of protein labelling when working with fluorescent labelling. Working in solution, taking into account viscosity, enables accurate RH determination of proteins in their native state, sticky proteins and proteins at high concentration. The use of a protein databank (PDB) algorithm links the theoretical and actual RH prediction with structural data. We suggest that greater protein QC insight will facilitate improvements in structural and biophysical studies.
