• Question: Is DNA fragile?

    Asked by meghop91 to Anouk, Chris, Judith, Leisha, Seyyed on 19 Jun 2012.
    • Photo: Judith Sleeman

      Judith Sleeman answered on 19 Jun 2012:

      DNA is actually quite a tough molecule: especially in the nucleus, where is is wrapped up really tightly with proteins to help protect it. It has been possible to get small amounts of DNA from some very ancient skeletons and Egyptian mummies, but the DNA is not of the best quality and hard to work with.

      We wear gloves and lab coats to handle DNA in the lab mostly to make sure we don’t get our samples cross-contaminated, not to stop the DNA from being damaged.

      RNA is a bit more fragile, which is why cells use RNA as a short-lived message and as ‘tools’ in gene expression that get replaced regularly, but has DNA for the genome. Some viruses, however, do use RNA for their genome.

    • Photo: Chris Kettle

      Chris Kettle answered on 19 Jun 2012:

      Yes and no. E.g. Fragile x syndrome is a well known disease. Basically DNA becomes unstable after expanding and breaks- this affects a particular gene and causes mental retardation.

      No- as DNA survive millions of years and still be useful today.

      Given the wrong conditions and it’s gone in minutes- provide the right conditions and it’s here forever

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