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Electrophoresis: SingleStrain vs DoubleStrain DNA chain speed

  1. Mar 17, 2005 #1
    Why does single strain DNA moves slower then double strain DNA in gel electrophoresis?

    I think that it is because single strain DNA has less electrical charge than double DNA helix, and single strained binds with H bonds uncharged molecules thus increasing it’s mass.
  2. jcsd
  3. Mar 17, 2005 #2


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    Single stranded DNA is relatively unstable nature; in the absence of a complementary strand, the single strand may experience intrastrand base pairing, resulting in loops and folds that give the single strand a unique 3D structure, regardless of its length. A single nucleotide change could dramatically affect the strand's mobility through a gel by altering the intrastrand base pairing and its resulting 3D conformation (Melcher, 2000).
  4. Mar 18, 2005 #3
    Please excuse my bad language.

    OK, forming secondary structure… I was thinking on Single stranded DNA in denaturated gel or denaturated Single stranded DNA (urea), which can not form intrastrand bonds.
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