do small pieces of DNA form a helix - (Oct/31/2009 )
Hello all. This might be a silly question, but if I PCR a 200bp piece off a plasmid, does that 200bp piece form a double helix or does it remain pretty straight? At what bp cutoff does it keep straight or form a double helix? Thanks!
-scientistI-
scientistI on Oct 31 2009, 01:39 PM said:
Hello all. This might be a silly question, but if I PCR a 200bp piece off a plasmid, does that 200bp piece form a double helix or does it remain pretty straight? At what bp cutoff does it keep straight or form a double helix? Thanks!
Sure it is (because of its hydrophilic Phosphate group and hydrophobic base). But, if it's too small such 2-8 bp molecule might be in the other stable form.I think
-GAome-
i also think that a 200bp sequence should form a helix.thats coz when a helix is formed, there are ~10 bp per turn.thus when the 2 complementatry strands will come together, they will bp and form a helix. A 200bp double strand would have less than 20 turns of the helix though..
-Helios-