MAGNETIC SEPARATION TECHNOLOGY
Biotech applications, ever more frequently, are requiring the isolation of biological components from complex mixtures. Current technologies to recover cells and biomolecules from blood and plasma are slow, inefficient and only work on small volumes. Via rational design of high-gradient magnet arrays combined with planar flow separation chambers, 42Bio has developed a faster, more scalable and more efficient technology for isolating various cell types and biomolecules from complex biological fluids. Magnetic particles bound to stem cells and biomolecules respond rapidly to our proprietary magnet arrays, facilitating highly efficient separation from larger volumes over very short time periods.
Collection of Blood Proteins
- Growth Factors
- Treatment of Septic Shock (septicemia)
- Vaccine Purification
- Gene Therapies
- Protein Complexes
Harvesting of Cells From Blood
- Stem Cells
- Immune Cells
- Cancer Cells
How it works
In the lab setting, components are routinely separated from mixtures using magnetic separation techniques. 42Bio's magnetic separation technology method works equally well for large components like whole cells, to small components like single molecules or peptides.
- In the typical setup, a magnetic micor-or nano- particle is functionalized by attaching a binding agent to the surface of the particle. The functionalized magnetic particle is then dispersed into a solution containing the target.
- The binding agent on the magnetic particle forms a bond with the target, "tagging" it for separation.
- With the magnetic particle and the target bound together, a magnetic field is applied to the solution. The magnetic particle's attraction to the field source pulls the target onto the surface of the separation chamber.
- With the particles and tagged components firmly held to the surface of the separation chamber, the rest of the liquid can be removed from the sample and residues washed with fresh buffer.
- In order to collect the components that were bound to the magnetic particle a releasing agent is added to the pellet. This release agent disrupts the bond between the particle and the target and releases the target into solution.
Illustration of the principle of magnetic separation. Diagram credit: 42Bio. Click image to enlarge.
Overcoming conventional challenges in magnetic separation
Current magnetic separation technologies either employ a magnet attached to the side of a small tube, or a small tube with a magnetizable mesh inside. In the latter case, when a magnetic field is applied, the mesh becomes magnetized, trapping the particle/target components. However, there are significant limitations to both of these approaches. These techniques work well for small separation volumes but there are significant limitations when voulumes or flow rates are increased. The rapid drop in magnetic field strength and gradient with distance from the magnet means that using tubes with larger diameters does not generate enough force on particle/target complexes flowing through the middle of the tube. Stronger/larger magnets work to a degree, but the exponential decay of the field limits eve this approach. In the case of magnetizable mesh systems, a second issue is clogging. As more particle/target complexes are trapped in the mesh, flow becomes blocked, significantly limiting the processing volumes.
Using a rational engineering approach 42Bio has solved these challenges. Instead of relying on increasing the size of the magnet, we have developed novel magnet array geometries that distribute high magnetic fields and gradients over a planar surface, enabling easy scale-up to large fluid volumes and flow rates under planar flow conditions. Our patented device for the separation of magnetic particles spreads the volume out into a thin sheet where the penetration of the magnetic fields is significantly enhanced. That is to say that there is more magnetic field/gradient density per unit volume in our geometry. This enables easy scalability while maintaining high target separation efficiency. While the components of this approach seem relatively straight forward, it is the integration and balance of all of these aspects that is the key to 42Bio's new technology.
The role of volume and magnet size on the mangetic field. Click image to enlarge.
42Bio's approach to overcoming technical limitations of magnetic separation: different geometry means better penetration. Click image to enlarge.