Denaturation and Replication of Nucleic Acid

I'm supposed to be storyboarding and creating an animation to demonstrate the process of Polymerase Chain Reaction, or PCR. It's a molecular biology technique by which one can exponentially increase the amount of DNA one has for an experiment.

The difficulty is that I've seen animations of this before, and they're all remarkably dull. Witness.

Not that I'm looking to steal any ideas, but I have no visual metaphor to work with. I want to make this interesting and tasteful. I want an animation that will look somewhat sophisticated, something that would challenge my design skills.

I do not want to make lines that separate and come together. Separate. And come together.

Even though, ultimately, that's what PCR is. It's just that the lines keep multiplying. I had thought about using a zipper as a visual metaphor, but not only has it been done to death, zippers don't multiply. Can you hear me, scientific media designers? Zippers do not multiply. I had thought to use a typewriter, and a scrolling sheet of paper with lines of As, Gs, Cs, and Ts, but I'm not sure if that's appropriate either. But it would be cooler to have an "intelligent typewriter" creating negative copies of lines of text.

In the end, I think I'm probably going to make lines that separate and come together, but this is a creative battle I don't want to lose. My storyboard is due two days ago, but creating what's already been created is basically plagiarism, only without the ease that plagiarism generally affords. I hope I'm not this dumb.