These magnetic beads range from 35nm up to 4.5μm.
That is, only one species of fragment will be present on the surface of each magnetic bead.
In this particular application, the magnetic bead is attached to a poly T tail.
Today, the assay characterized by using Silica coated magnetic beads seems the mainstream.
Re-suspension of the captured magnetic beads are in detail, consists of the following steps.
The magnetic bead is attached to the opposite end via biotin-streptavidin interaction.
The magnetic force can be easily adjusted by changing the distance between the trap and the magnetic beads.
They have a different diameter as the magnetic beads so that they are optically distinguishable.
Presently many studies utilize magnetic beads for this step.
An added benefit of using magnetic beads is that automated immunoprecipitation devices are becoming more readily available.