Provided are techniques that may include a disposable magnetic cell isolation holder having one or more passages that accommodate a magnetic retention material to facilitate magnetic cell isolation without adjustment of magnetic field parameters between isolation procedures using different magnetic particle sizes. When the magnetic cell isolation holder is coupled to a magnetic field generator, a first passage corresponding to a smaller particle size is positioned in a magnetic field where the magnetic field characteristics are different relative to a second passage, of a second holder or in the same holder, for use with another bead size.