Biomagnetic Separation

The inherent ability of magnetism to separate ferrous objects from mixtures has been utilized for years. In recent years, due to advances in both chemistry and manufacturing, the benefits of this separation technique have been realized in the biomedical field. Applications span the gamut from RNA and DNA isolation to immunology and purification. The key components of any biomedical magnetic separator are the activated magnetic particles and the magnetic fields that separate them. Activated magnetic particles consist of tiny magnetic volumes coated with an affinity ligand. When these coated particles are placed into a liquid, they attract, and hold, certain cells, based upon the coating selection. Once sufficient time has been allotted, the entire volume of liquid is exposed to a magnetic field that 'pulls' the magnetic particles, with cells attached, to a predetermined location. The remaining liquid in the volume can then be removed, and a sample of specifically selected cells remains.

The shape and magnitude of the magnetic fields determine the location where, and the speed with which, the particles separate in any given vessel. Both permanent magnets and electromagnets can be utilized to produce the required magnetic fields.

The two components of the magnetic field that play vital roles in separation are the field magnitude and the field gradient. The force applied to any given particle is linearly proportional to these two variables. Therefore, if these two variables are known at every point within the separation vessel, calculations may be performed to determine the relative force densities within that active volume. By comparing these relative force density values, one may gauge the effectiveness of one separation magnet against another. As a rule of thumb, the higher the relative force density, the smaller the particles, and the more quickly a given magnet can separate.

For further inquiries, please e-mail us at info@dextermag.com -or- call us at:  800-345-4082 (In North America) or +44 (0) 1189 602430 (In Europe).