If scientists and technicians link their production results solely to the separation time on one specific piece of classic biomagnetic separation equipment, they will not be able to translate that success. This is applied to both different batch sizes or even the same batch size on a different piece of equipment, unless they optimize the separation time for the new conditions.
When a lab has finally optimized their production process, they often link their process to a very specific piece of equipment and, by extension, have locked themselves into a constant volume. Often a lab develops its magnetic separation process for production with a specific magnetic separation device – this is normal. Usually the only parameter that needs to be adjusted during production is the separation time.
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.
If one wants to scale up production from small lab lots to full-scale large lots, a non-homogenous magnetic separation process will result in lot-to-lot inconsistencies. Homogenous biomagnetic separation conditions, however, guarantee consistent results regardless of production scale.
Magnetic separation is a breakthrough technique for in vitro diagnostics (IVD). Scientists, hospitals and companies have taken advantage of the magnetic separation process for immunoassays, molecular diagnostic and genetic testing systems and kits. However, this type of technology is typically utilized by the end-user in very small quantities.
In-lot consistency is the key to reproducibility at the level of a kit. Unfortunately, in non-homogenous systems irreversible aggregation is one of the main sources of in-lot variability. If all of the beads are exposed to the same force as they are in homogenous magnetic systems, the risk of aggregation is greatly reduced. Because of this, it is important to know how to avoid irreversible aggregation problems during a magnetic separation process.
A recognized problem in the biomagnetic separation industry is that when one increases the batch size to scale up production of magnetic beads, the magnetic separation process time increases unproportionally to the increase in volume if one is working with standard magnetic separation devices.
One of the biggest problems of producing magnetic beads when scaling up the production is that compared with smaller lot production, larger lot production seems to result in a much larger disproportionate loss of beads. This seems to happen even when the beads are produced in conditions that are similar to the small lot production in a magnetic separation process. The assumption is that when you scale up a process, you will have greater efficiency, but this does not happen when scaling up production of magnetic beads using classical separators.
By Lluis M. Martinez, CSO Sepmag
Often when a lab produces a product that becomes popular, the impetus is to move forward and scale up production of that product. The problem is that moving from the production of small lots to full scale production usually produces surprising results. Scaling up is not trivial, and the magnetic separation process is no exception. When one scales up production, results become very inconsistent.