The Consenxus asymmetric flow field flow fractionator (AF4) is a specialized chromatography system that separates molecules based on size without the use of a chromatographic medium or packing material. The separation is based on the diffusion of the components of the solution in a narrow channel undergoing laminar flow following a focusing step where the components are retained against a semi-permeable accumulation barrier. Detection of the effluent is via differential refractive index (RI) and multi-angle laser light scattering (MALS), allowing for characterization of the particle size distribution and radius of gyration. AF4 has advantages relative to GPC/HPLC based separations for particles that may interact with the column packing material or that are larger in size. AF4 typically can resolve components on the 1nm to 1um size scale with a very large dynamic range.