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When scaling up a process using a traditional magnetic separation rack, the percentage of bead and biomolecule losses significantly increases with an increase in volume. One way of dealing with this problem is by applying a higher force at longer distances. But for this to work, you must apply this greater force without increasing the forces in the retention area during the magnetic separation process, in order to avoid irreversible aggregation.

A homogenous separator exerts the same force on all beads regardless of their position in the vessel, allowing the technician to use lower magnetic forces during the process. Under these conditions material loss and aggregation are mitigated.

This post is about biomagnetic separation in the production of magnetic beads for IVD kits. If you want to know its most important elements, download our free ebook The basic guide to use biomagnetic separation in production processes:

## Avoiding material losses during Production with magnetic bead separation

In standard magnetic separators, the magnetic field decreases with distance and the force decreases even faster with distance. Therefore, in a large scale production, fewer beads are captured with the same separation time used in smaller scale productions. Since the force decreases more quickly than the distance the beads travel, time needs to be increased by orders of magnitude (near exponential increases) in order to maintain a constant level of loss.

In order to avoid these material losses by maintaining the same force value over the beads farthest from the magnet when the volume of the vessel is changed, your beads will experience much higher retention forces at the walls of the vessel. In addition, the time of separation will need to increase as the distance the beads need to travel increases in larger vessels. However, when you have higher retention forces over a longer period of separation time, you increase the risk of irreversible aggregation.

In addition to these problems with classic magnetic separators, the cost and weight of the separator scales up much more quickly than the useful working volume increases.

The only way to overcome these significant material losses from standard biomagnetic separators is to switch to more modern systems that generate homogenous force conditions regardless of the distance from the beads to the magnet. Since the force is constant over the entire volume, losses are constant and the separation time will be linearly dependent on the distance the beads need to travel. Since the retention force is much lower than when using classic separators, the risk of irreversible aggregation is much lower.