Devices for separating magnetically labeled moieties in a sample are provided. Aspects of the devices include a magnetic field source, a first magnetic field guide having a wedge-shaped portion with an apex edge, and a second magnetic field guide having a wedge-shaped portion with an apex edge. The apex edge of the first magnetic field guide is aligned substantially across from and parallel to the apex edge of the second magnetic field guide, and the device is configured to separate magnetically labeled moieties from non-magnetically labeled moieties in the sample. Also provided are methods of using the devices, as well as systems and kits configured for use with the devices and methods.