Magnetic sequencing is a single-molecule sequencing method in development.  A DNA hairpin, containing the sequence of interest, is bound between a magnetic bead and a glass surface. A magnetic field is applied to stretch the hairpin open into single strands, and the hairpin refolds after decreasing of the magnetic field. The hairpin length can be determined by direct imaging of the diffraction rings of the magnetic beads using a simple microscope.  The DNA sequences are determined by measuring the changes in the hairpin length following successful hybridization of complementary nucleotides.