A process for separating a protein from a sample containing a mixture of proteins is disclosed. The process comprises forming an aqueous combination comprising the sample and an ion exchange material at a pH which is less than the pI of a first fraction of the proteins in the aqueous dispersion but greater than the pI of a second fraction of the proteins in the aqueous dispersion. The aqueous dispersion may then be intensely mixed, causing a fraction of the proteins in the combination to bind to the ion exchange material, and, optionally, centrifuged, causing the combination to stratify into a concentrated solids fraction and a supernatant, the supernatant containing the fraction of the proteins that did not bind to the ion exchange material. This process, including the steps of intense mixing and centrifugation, requires no expensive, specialized instrumentation, can be quickly performed, and is carried out in non-denaturing conditions, allowing for the separated proteins to be further studied.