Nucleic acid (DNA and RNA) is essential for life. So if you project involves the molecular scale of life, there is a good chance you're going to need some DNA. If your project is of educational value, it's important that the DNA twists the correct way and that both the minor and major grooves are present. If not educational, having the correct details adds a level of professionalism and credibility to your project.
This set contains 4 different models of DNA that show different aspects of the molecule; Simplified, Bonds, Atoms, and Surface. Each model consists of a single twist and is set up with an array modifier and a follow curve modifier. This allows you to import the representation of choice and quickly make it as long as you need for your scene. The set also includes a curve and empty if you want to make your own version of a simplified DNA Strand.
The set was assembled in Blender 2.79, the materials use the Principled BSDF shader with a noise modifier adding some bump for visual interest. The Bond, Atom, and Surface models are colored by atom. With each atom having its own material. The Simplified model is colored by nucleotide (A,T,C,G) and another material for the backbone. Once again, as separate materials. The aqua color in all for models comes from the subsurface color. This can be changed to match your project.
For those you wondering what the sequence is, it is TACGATTACA. TAC (start codeon) GATTACA (1997 movie).