Magnetic-assisted rapid aptamer selection (MARAS) for generating high-affinity DNA aptamer using rotating magnetic fields.

A new SELEX protocol for the development of DNA aptamers has been demonstrated, referred to as magnetic-assisted rapid aptamer selection (MARAS). This method uses magnetic beads and an externally applied rotating magnetic field to provide the competitive mechanism for the selection aptamers with different affinities to the molecular target. The MARAS protocol efficiently generated aptamers with high affinity and specificity for C-reactive protein, a common cardiovascular disease indicator. The binding affinities of the selected aptamers could be varied by changing the frequency of the externally applied rotating magnetic field and optimal cases bound with low-nanomolar dissociation constants.