And so what that means is we need three different things. We need a DNA primer, we need DNA polymerase and we need the building blocks, the four types of normal deoxy nucleotide triphosphate. So in step two, the solution containing the single strand of DNA, this one here is mixed with number one or a a labeled radioactively labeled DNA primer. So we need the DNA primer basically for that DNA polymerase to actually work. Because remember, the DNA polymerase will only initiate replication if the primer is present. And what that means is we have to know what this initial sequence is on that DNA molecule.