And so just like in diagram one, where we knew exactly what the sequence was and so we knew what type of sequence to build on that DNA primer. Now we also know what sequence that DNA primer should have. If this is a polygtail, we have to build a polyceetail. And so in step five, we build a polyceed DNA primer. We add it into our mixture and at the right temperature, these two will anneal. They will hybridize.