HomeHow to avoid In-lot inconsistency when scaling up biomagnetic separation processes
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Small volume classic magnetic separation racks are relatively cheap and do a fairly good job at separating magnetic beads. However, if the process involves multiple instances of capture and elution steps, irreversible aggregation becomes a real problem. In small volume separations (i.e. on the order of milliliters), using the appropriate techniques can give you excellent re-suspension results.
Large volume classic magnetic separation racks, however, typically have serious problems with irreversible aggregation. The way to avoid losses in magnetic bead yield is to increase the magnetic force. Since magnetic force in classic separation devices varies with distance, increasing the force causes beads close to the magnet and in the retention zone to experience extremely high forces over a longer period of time. Consequently, the magnetic beads have a higher probability of being irreversibly aggregated, forming clumps by overcoming the electrostatic barriers that normally keep the beads apart from one another. When the electrostatic barriers are breached, the beads become cross-linked. This irreversible aggregation and clumping effect inlot consistency adversely because aliquots for individual kits from the same large volume lot are highly variable. Some beads were exposed only to a low magnetic force and some were exposed to very high forces.
There are two possible ways to deal with these inconsistencies:
1.You can devote a large amount of resources (money, materials, time, and personnel) toward recovering beads from the aggregates (i.e. using sonication and long sonication/homogenization cycles).
2.You can use a homogeneous biomagnetic separation system like SEPMAG.
Beads produced with a homogeneous system and a wisely chosen magnetic force value will produce lots that are consistent throughout the entire volume since the same force is felt by all of the beads.
Large volume classic magnetic separation racks, however, typically have serious problems with irreversible aggregation. The way to avoid losses in magnetic bead yield is to increase the magnetic force. Since magnetic force in classic separation devices varies with distance, increasing the force causes beads close to the magnet and in the retention zone to experience extremely high forces over a longer period of time. Consequently, the magnetic beads have a higher probability of being irreversibly aggregated, forming clumps by overcoming the electrostatic barriers that normally keep the beads apart from one another. When the electrostatic barriers are breached, the beads become cross-linked. This irreversible aggregation and clumping effect inlot consistency adversely because aliquots for individual kits from the same large volume lot are highly variable. Some beads were exposed only to a low magnetic force and some were exposed to very high forces.
There are two possible ways to deal with these inconsistencies:
1.You can devote a large amount of resources (money, materials, time, and personnel) toward recovering beads from the aggregates (i.e. using sonication and long sonication/homogenization cycles).
2.You can use a homogeneous biomagnetic separation system like SEPMAG.
Beads produced with a homogeneous system and a wisely chosen magnetic force value will produce lots that are consistent throughout the entire volume since the same force is felt by all of the beads.
