MagSi-Direct provides a convenient and efficient way to attach virtually any biomolecule to nanoscopic paramagnetic beads. It is particularly suited for exploiting interactions between a biomolecule and its binding partners. With MagSi-Direct, you can start with a molecule of interest, attach magnetic beads to it, and then use a magnet to isolate that molecule from any desired reaction mixture, together with any other molecules, complexes, or even intact cells to which the starting molecule has bound. In effect, the starting molecule is converted into a magnetic affinity reagent, or "bait", which can be used to purify, isolate, or characterize the partners with which it interacts.