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How Long Should DNA Strands Be?

Do these simulated DNA strands seem about the right length to you?

This is not a purely abstract question (pun intended). Complementary strands of DNA are drawn to one another like magnets and iron filings – a trait that has created the emerging field of DNA self-assembly. But research, and industrial application, in this area has been hampered by a lack of reliability in how the DNA behaves. Sometimes it works great. Sometimes it doesn’t. But scientists have now made a breakthrough that should help resolve that problem, and move the entire field forward.

DNA self-assembly is based on the idea that you can coat two different materials with complementary DNA, and that those two materials will come together when the DNA strands are drawn to each other. But the length of those DNA strands is important. If they’re too long, they’ll get tangled up with each other before they can find their “mate.” If they’re too short, they fold over onto themselves.

New research from NC State and the University of Melbourne shows that DNA strands should be longer than 10 bases, and shorter than 30 bases, to promote optimal self-assembly (remember, DNA is made up of base pairs). The researchers reached their conclusions using computer simulations to assess the behavior of DNA strands. The paper is published in Langmuir.