The 25th may have been and gone but don’t go getting those post-Christmas blues just yet! Here’s some fun science for you!
DNA Origami may not be something you’ve come across. Now before you start collecting up all that discarded wrapping paper that’s inevitably still strewn around the living room, it’s not quite the type of origami you might imagine. Far from making a quirky little double helix out of folded paper, DNA Origami uses lengths DNA to form nanoscale structures.
From rectangles and robots to shapes and smiley faces, this process of designing and making 1-, 2- and even 3-dimensional shapes relies on the intrinsic ability of DNA to self-anneal. By using different lengths of single-stranded DNA (long strands to act as a scaffold and short strands called “staples”) the DNA can be manipulated into nearly any shape you can think of!
What happens is the short strands are carefully chosen to have a complimentary sequence to the long strand. For example, the Ts, Gs, As and Cs in the long strand will be complimentary to the As, Cs, Ts and Gs in the short strand.
Once the two strands have annealed and the reaction takes place under the right conditions, the longer strand will distort in shape. As you can imagine, using lots of specifically designed staple strands in the correct locations you can bend, weave and loop the DNA into all sorts of different shapes!
Whilst this is pretty cool stuff and can be fun to look at down a microscope, it’s admittedly not that practical.
However, by using Computer Aided Design in combination with a DNA synthesiser, scientists can start to build 3D structures out of DNA. For example, they can introduce specific folds into DNA to make it assemble into a box shape. This box can be used as a drug delivery vehicle as it can be introduced into the body and open upon stimulation with a specific wavelength of light, releasing the drug for treatment.
Work is also underway to see if DNA Origami can be used to make DNA which can conduct electricity when coated with a specific type of polymer.
The uses and applications of DNA Origami are still quite limited. It does, however, show us that technological advancements and medical improvements really do go hand in hand, particularly on the nanoscale.
Feature Image: http://howtosmile.org/record/9018
(i) Rothemund (2006) (ii) http://www.newscientist.com/articleimages/dn8853/1-dna-origami-creates-map-of-the-americas.html
Rothemund PW (2006). Folding DNA to create nanoscale shapes and patterns. Nature, 440 (7082), 297-302 PMID: 16541064
Han D, Pal S, Nangreave J, Deng Z, Liu Y, & Yan H (2011). DNA origami with complex curvatures in three-dimensional space. Science (New York, N.Y.), 332 (6027), 342-6 PMID: 21493857