What’s wrong with this picture?

Quality assurance, or QA, is a job encompassing editorial revision and functional testing. It also curses QA analysts. We cannot unsee common errors and they shine like a hot needle in our eyes, jumping out unexpectedly and pulling our concentration into Revision Mode. We’re like the Terminator armed with resizable red ellipses.

One of the most insidious offenders is Left-Handed DNA, as described in this post on Symbiartic at Scientific American. Imagine that DNA is like a ladder that’s been twisted: you can turn it two ways. The way it is twisted is referred to as the ladder’s chirality, which means the mirror images of a molecule are not chemically the same as each other. In the case of the ladder-like shape of DNA, you can twist it left or right, counterclockwise or clockwise.

All DNA on Earth is right-handed: it twists clockwise. It’s one of the many indications we have that all life on Earth has a single common ancestor. Left-handed DNA is virtually unknown, (save for the form known as Z-DNA; when people speak about DNA generally, they are referring to the common B-DNA form].

But you wouldn’t know it to look at depictions of DNA in popular culture.


Jurassic World official site: “Maybe we would have noticed earlier if Hammond had not spared the expense of graphic cards that support more than one colour.”


Screenshot from the Word Crimes video by Weird Al: For such a nitpicky song about grammar, we’re disappointed in you, Weird Al.


From the opening of the videogame Assassin’s Creed: Unity. Apparently Abstergo Industries is using their civilization control methods to spread misinformation via their Helix machine.

time_healthTIME Magazine, Healthland: Exercise can’t change your DNA that much, TIME.

A quick look through the world of digital health online also finds backward DNA running rampant. We’ll refrain from sharing. Oh, okay—just a couple:


Oh, Elsevier Genetics. But wait! They have recently rebranded!

Oh. Missed opportunity, that.

These examples are far from alone. Digital health companies – check your logos! 


And using stock images? Fuhgeddaboudit. [Edited image a screencap of a Google search for “stock images DNA”]

The ramifications for depicting DNA in an erroneous configuration are pretty low – this left- or right-handed flip is not as severe as illustrating an incorrect limb to amputate prior to surgery, for example. And so there is little urgency for studios and agencies to be on the lookout for the twisty mistake. We’ve even spotted it on the Twitter account of a pharmaceutical industry review board.

To make certain that left-handed DNA doesn’t contaminate our graphics and animation here at INVIVO, we recently undertook the massive task of reviewing our back portfolio of animation images, to make sure any examples of this common error do not see the light of day.

If you’re curious if you may have made an error with backward DNA,  make use of this handy graphic, developed by our Quality Assurance team from one of our animation reels:


..and now that you’ve seen left-handed DNA, can you unsee it?  If not, you could be ready for a career in biomedical quality assurance!

Disclosure: Our backward-DNA-seeing author, Glendon Mellow, writes for Symbiartic alongside Kalliopi Monoyios, the author of the backward DNA post mentioned at the beginning of the article.