Select your geo Animation menu set > Create Deformers > Non-linear > Bend. Rotate the bend control to be parallel and the same length as your DNA strand. Then increase the curvature in the channel box (3.14 will give you a full circle). Make sure you have -1 to 1 in the low bound to high bound. I found it already but thank you. It looks almost like what I wanted, just need to make a longer helix for more DNA loops. Actually, I think the DNA loops are enough, when in close-up they look great. Thank you all!