You might think that creating the highly recognizable double helix of a DNA strand might need special and costly add-ons for After Effects. Not so. You can actually create a nice looking 3D-like DNA animation simply by using vector shapes and a few tricks.
learn how to create a 3D DNA strand using the free built-in tools and effects in After Effects
There, Caleb Ward shows how you can create a faked 3D effect by cleverly duplicating vector shapes in After Effects, so they will look natural in a 3D environment. Using nested composition, and continual rasterization is the key to the effect. Adding some expressions allows you to easily create the double helix shape by simply duplicating compositions.