So, to see exactly what we mean, let's take a look at the following diagram. So in this diagram, it is before we added that DNA probe. And so if we zoom in on this band, band C, we basically get this double stranded DNA molecule has been denatured. And so these two individual single strands exist as single strands. Now, when we add that DNA probe that has been radioactively labeled by, let's say, a heavy phosphorous atom, so what will happen is, because the sequence is complementary to this sequence here, the green radioactively labeled DNA probe will hybridize, will form a double helix structure with that single stranded complementary molecule. And so now this has been radioactively labeled.