When synthesizing DNA strands and beginning to "connect" them, how quickly does it become a helix?
In this answer, canadianer says
The helical structure is more stable than the "straight" form (because of base stacking interactions), and so it forms spontaneously.
This then makes me think of the following scenario: say one is constructing two strands of DNA out of deoxyribonucleotides. Then, one begins connecting them with hydrogen bonds. Before the hydrogen bonds are added, my understanding is the two strands would be straight and not helical (if this is wrong, please correct me on this) so at some point as the two strands are connected, it would "spontaneously" become helical.
The question, then, is at which point. After one "connection"? Two? All of the connections necessary to complete the piece of DNA?