ABC science news: It’s a small world
An artist's impression of the i-motif DNA structure inside cells. Illustration: Chris Hammang.

An artist's impression of the i-motif DNA structure inside cells. Illustration: Chris Hammang.

Today I talked with Jacinta and Sami about unexpected findings in science on the small scale on ABC Melbourne 774.

Listen from 1:04:37 at (expired)

New type of DNA discovered

If you did any science in high school you will probably remember that DNA as we know it looks kind of like a long, twisted ladder called a double helix.

And up until now, that was it. There has been one type of DNA that scientists knew existed in the human body, and it was the double helix.

But, in exciting news, that’s no longer the case. Scientists out of the Garvan Institute in New South Wales have confirmed the existence of a new sort of DNA in living human cells. This new DNA, called the i-motif, is shaped like a twisted knot.

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What this means

This is an exciting discovery because understanding the double helix (discovered in the 1950’s) allowed scientists to begin unravelling the mysteries of genetic code. This led to major developments in disease screening and treatment, food production, and forensic science.

So, discovering a whole new type of DNA could potentially open the door to a whole range of new discoveries about the human body.

Having just confirmed their existence, we don’t yet know what the function of the i-motif is. But there was something interesting about the discovery that could lend a clue as to what their function might be.

What really fascinated the team was that the i-motifs were observed to be appearing and disappearing. This could indicate that it may be responsible for turning genes on or off. Genes turning on or off is what accounts for our attributes, which can be minor things like hair colour and eye colour, but also inform more important things like how our bodies respond to lactose, or protect us from cancer cells.

Scientists actually have seen the i-motif before, but only in lab conditions, and weren’t sure whether it could possibly exist inside living things. This discovery provides proof of the i-motifs existence and opens up the doorway to a whole new world of exploration into gene science.

Engineers discover how to bend diamonds

When you think of bendy, stretchy naturally occurring materials you might think of rubber or even bamboo. Chances are, diamond, the earth’s hardest known naturally occurring material, doesn’t enter your thoughts.

So it’s surprising that a team of engineers has figured out how to bend diamonds. Yes, that’s right. That extremely hard, yet extremely brittle material that will normally break if bent even a tiny bit, can be flexible.

How they did it

They did this by looking at the diamonds on the nanoscale (smaller than what we can see with a microscope). At this scale they found that the diamonds behaved quite differently to how they behave at the human scale.


On this scale, when they bent the diamonds, the engineers saw that they could stretch by around 9% and then bounce back to their original shape without breaking at all – a complete surprise even to these engineers.

What does this mean?

This discovery is unlikely to mean bendy diamond jewellery (although I’m not sure what possible market there would be for that anyway) but it does have far more interesting and useful applications.

Now that we know about this flexibility in diamonds at the nanoscale, it could advance research in a whole variety of medical and technological fields because that hardness.

Some possible applications that scientists have already been talking about include:

  • using diamond nano-needles to deliver drugs to the heart of cancer cells
  • improving data storage devices
  • more powerful lasers
  • using the technology in quantum sensors (up to 100 million times more sensitive) for navigation, telecommunications.

This result is another reminder that the world is VERY different at the nanoscale and that the laws of physics as we know them at the human scale, don’t apply in the nano-world. For example, on the human scale, we can’t walk up to a wall and just teleport to the other side. But at the nanoscale an electron can – it’s called electron tunnelling.

Sometimes in science, as in life, forgetting what we think we know and being open to new possibilities can lead to really cool things.

Jillian Kennydna, nanoscale