The DNA sample is mixed with the magnetic beads. The beads contain specific sequences that will bind selectively to the DNA molecules. When placed in a magnetic rack, the beads will be separated from the solution. We can then pipette away the solution containing all the unwanted materials (such as buffers and enzymes) and wash the beads using 80% ethanol. After several rounds of washing, we can elute the DNA molecules from the magnetic beads and transfer them to a new tube.