2015-05-042015-05-042011-05-10Colvin, Vicki L., Yavuz, Cafer Tayyar, Mayo, John Thomas and Yu, Weiyong, "Magnetic purification of a sample." Patent US7938969B2. issued 2011-05-10. Retrieved from https://hdl.handle.net/1911/80054.https://hdl.handle.net/1911/80054Methods for separating magnetic nanoparticles are provided. In certain embodiments, a method is provided for separating magnetic nanoparticles comprising: providing a sample comprising a plurality of magnetic nanoparticles; passing the sample through a first magnetic field; at least partially isolating nanoparticles of the first nanoparticle size desired; altering the strength of the first magnetic field to produce a second magnetic field; and at least partially isolating nanoparticles of the second nanoparticle size desired.25 ppengUtility patentUS7938969B2