When a biotech company or other related industry decides to use biomagnetic separation technology, a great deal of time, energy and resources are typically spent by R&D and manufacturing departments to determine the optimal bead to use for their specific applications. Often, however, they overlook one of the major determinants of separation: homogeneity of separation conditions.
This post is about magnetic bead separation and how to validate this process. If you are interested in this topic, and are willing to learn more about it, download our Free Guide The Starting Guide to Validate Biomagnetic Separation Processes:
Traditional magnetic separators
When traditional magnetic separators are used (both classical open magnet and rod-like systems), the beads experience non-homogenous magnetic forces and fields depending on the distance the beads are from the magnet. Some beads will be far from the magnets and some will be close, therefore the separation conditions and microenvironment that each bead ‘sees’ are different. Beads close to the magnet will experience magnetic saturation while beads farther from the magnet experience varying magnetic fields as they travel toward the magnets.
In addition, beads farther from the magnet will be more difficult to attract due to the low magnetic forces. Beads close to the magnet experience excessive forces for longer times causing an increase in bead aggregation, loss of bead activity and problems with resuspension. Laborious sonication is necessary to recover aggregated beads. One can easily see that beads existing in the extreme magnetic force regimes (near or far) are generally difficult to recover completely.
Sepmag systems
In contrast to traditional systems, Sepmag systems are designed so that every bead experiences the same magnetic force, regardless of its distance from the magnetic ring. Since beads ‘see’ the same magnetic force, the conditions are well defined and do not suffer from the inability to parameterize the process as in the previous case. Results are reproducible because the magnetic forces are homogeneous. In addition, processes can be scaled up without disrupting the homogeneous conditions. Variability in the end product is ultimately eliminated, no matter the size of your batch.
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