Tips for Working with Magnetic Beads

Magnetic beads

Protein purification with magnetic beads is an excellent choice for high-throughput microscale purification, pull-down/CoIP, and protein/protein or protein/DNA interaction studies. Magnetic beads can be coated with specific affinity ligands for antigens, antibodies, proteins, or nucleic acids.

Magnetic beads have a defined diameter and non-porous. There are no hidden surfaces for the molecules to stick to. So the background, purification, and washing steps are all reduced. Separation using magnetic beads is the quickest, cleanest, and most efficient technique out of all the bead separation methods using agarose, sepharose, or silica beads.

Here are some tips for new users.

  1. Resuspend your beads thoroughly to ensure consistency between the aliquots

Magnetic beads need to have enough magnetic contents to allow simple pull-down by a magnet. Our Magnetic Beads are nano-superparamagnetic beads covalently coated with highly functional groups. The increased beads surface area results in increased binding capacity and improved dispersion. Magnetic beads are massive particles comprised of iron oxide, so they sediment over time. It is crucial to vortex and thoroughly resuspend the magnetic beads before use to redisperse the beads.

2. Wash your beads to reduce non-specific binding

Increase the number of washing steps helps to reduce non-specific binding to the beads. When washing the magnetic beads with either ethanol or recommended wash buffer, use enough wash solution to cover the pellet. Understand the functional groups of your beads
Our beads covalently coated with maleimide, primary amine, NHS, carboxylic acid, purified streptavidin, protein A, reduced glutathione, nickel-charged nitrilotriacetic acid, or groups for DNA/RNA purification. The coatings, buffer conditions, and functional groups will affect the properties of the beads. It is essential to understand the necessary information about the beads to handle them better.

3. Capture the beads to ensure all beads are recovered

Generally, the magnetic beads are attracted to the magnet and form a pellet within a minute. Prolong the attraction of the magnetic beads to the magnet helps.

4. Do not disturb the bead pellet when removing the wash solution

Angle the pipette tip when removing the wash solution or supernatant. Do not let the tip touch the pellet of magnetic beads.