We make stir devices that create a powerful vortex and the centrifugal forces are strong enough to keep magnetic beads suspended.
Our part: VP 776-8-50DM is a demagnetized, round, PTFE encapsulated Alnico stir bar 50mm long & 8mm in diameter. When used in combination with the VP 710D2 Multi Stirrus™, your magnetic beads will remain in uniform suspension. They are only weakly attached to the stir bar, and the centrifugal forces easily dislodges them and keeps them from settling to the bottom of the bottle.
The same approach can be used for mixing magnetic beads in automation-friendly reservoirs with the use of our parylene encapsulated stainless steel bubble paddles.
Watch this video for a demonstration.