Its kind of iffy. Some doctor (named Rubinstein) was the one who pointed out "the sulphuric bridge appears in the following manner: every ten acids there was a bridge, every five acids a bridge, every six acids a bridge ... and again every five acids were a bridge." Specifically, there are 4 repeating bridges that connect the two DNA strands. The strands are held together by hydrogen bonds: two bonds between adenine and thymine and three bonds between guanine and cytosine. I'm not sure if this bridge pattern applies to all life or just humans but here is a video that explains more https://yewtu.be/watch?v=1tmJrxpJWuw