The researchers isolated messenger RNAs from each sample and converted each messenger RNA into complementary DNA sequences. They then split each double-stranded DNA molecule into a smaller fragment and attached molecular primers to either end of the fragment, creating a tag. Seidman mixed the genetic tags with magnetic nano beads. Through a polymerase chain reaction, the team cloned millions of the same DNA sequence tags on each bead. The result was an amplification of an otherwise weak genetic signal.