On-Screen Scientist

And now, a word from our sponsor. If you’ve ever wanted to learn or thought that maybe you should learn what the structure of DNA really looks like and how DNA actually works in our cells to make us who we are and keep us going, then you have a chance to do it in a very thorough and enjoyable way for the lowest price ever. OnScreen DNA, the virtual model programmed by the On-Screen Scientist himself, is on sale at a 70% markdown, in honor of DNA Day and the original discovery of the DNA double helix fiftty-five years ago. The price? Just $19.53 (where’d that number come from?), instead of the usual $69, through April 25, 2008.

What’s DNA Day? It’s the day we celebrate both the historic publication of the Watson and Crick paper that elucidated the double helical structure of DNA and the completion of the Human Genome Project. April 25 has been chosen as the day. I may feel moved to say something about the discovery one of these days, maybe even before DNA Day, but for now I wanted to alert my many readers to the sale.

The software runs on Macintosh OS X or Windows XP/Vista. Download the free OnScreen DNA Lite first if you wish to see the quality of the model. But you don’t really get the full how-DNA-works story in the Lite version, just a detailed guided tour of the structure, including the essential molecular components and chemical bonds. The on-screen tutorials explain everything you’re seeing, and practically no prior knowledge is assumed.

Can you spot the many (roughly 50% it seems) inaccurate popular depictions of DNA as a left-handed helix instead of the proper right-handed type? Well, you’ll be able to after a few minutes with OnScreen DNA (or even the Lite edition, for that matter). It would be so easy to tell the artists hired to make all these nifty DNA double helix logos and designs the difference between left-handed and right-handed DNA, but it seems no one does, even scientists. Witness the many backward examples. I think the professor that was maintaining the left-handed-DNA web site finally got tired of it, but I imagine the archives are still up in any case. Just Google it. New examples appear all the time. The Boston Globe had a doozy that occupied about half a page just last week. Left-handed DNA does exist in nature, but it’s a small percentage and is not the genome molecule of our chromosomes.

Anyway, the animations of DNA and RNA chain-construction in OnScreen DNA are a lot of fun. I still enjoy them after having seen them countless times during programming, debugging, testing, and just playing around. You really need to see the three-dimensional structure of DNA, not just the two-dimensional ladders which animations encountered on the internet seem to invariably fall back on. Having programmed the OnScreen DNA animations, I can see why. It’s a pain to do the three-dimensional programming. But it is worth it. Just go to <onscreen-dna.com/buy_dna_online.php> to purchase online and see for yourself. Or get the free version from the link in the upper right. Amaze your friends by pointing out the next picture of left-handed DNA you come across! That’s almost as good as ordering in French at the French restaurant.