Now it's cooled to a temperature of about 54 degrees Celsius. And that's just the right temperature for those DNA primers to actually anneal and hybridize with the three ends of those DNA strands that are now single strands. And notice these two strands of DNA will not form the hydrogen bonds because now we're going to have many of these DNA primers floating around and in between our two DNA strands. So the lower temperature will allow for the hybridization between the primers and the DNA and one DNA primer anneals to the three end of each one of these DNA strands. The reason we have the Anneal at the three end? Because the DNA polymerase, as we'll see in step three, always reads that DNA molecule beginning at the three end and moving towards the five end because it synthesizes from the five end to the three N. So this green primer is the primer that Anneales to the three end of this trend.