Magnetic Beads

Magnetic beads are small, solid particles used in the immobilization and separation of proteins, carbohydrates, antibodies, and cells. They contain an iron core that can be bound to or coated with various materials, conferring certain properties to the beads. Agarose covered beads are suitable for proteins as non-specific binding is reduced. Silica beads are used for the purification of nucleic acids. Beads conjugated to specific antibodies can isolate specific protein targets, antibodies, and even whole cells. Magnetic beads can provide certain advantages over other purification methods. Due to their non-porous nature, they have a higher binding capacity. Because magnetic separation does not require repeated centrifugation or filtration, there is less sample loss. Outside of purification, magnetic beads have also been used as carriers for imaging.