Policy on Images in the
Left Handed DNA Hall of Fame

NEW: Fair Use Policy

Starting on 2013 August 14 I will be posting images following the Fair Use copyright policy. This web page is not commercial and the images are presented for amusement and educational purposes so they fall under the Fair Use policy. I will often post without requesting permission, but will mark the image as 'Permission Requested'. However, I would appreciate it when you write to me to grant permission.


Images on the Left Handed DNA Hall of Fame are marked by one of four icons, according to a `traffic light' scheme:

When a source acknowledges the error and makes some move to correct it, they earn a thumb's up: .

Removal of Images

Sometimes people who have published left handed DNA images request that they be removed from or not included in the Left Handed DNA Hall of Fame.

I'm of two minds about removing cases. First, I will respect your wishes about the image. Second, I will also respect your wishes about a link. However, I'm somewhat reluctant to remove images and links because that means that the cases left in the 'Hall' would be all unresolved. If all cases were removed the Hall would become less interesting. So in cases where people correct the image I give them a 'thumbs up': In a case in 2000, one group reversed their image so fast that we almost missed it! Both images are there now. I think that such cases encourage other people to make corrections. Everybody makes mistakes, me included! The question is what one does when there is a mistake. In the worst case I know, a group at a famous medical school made a poster that was checked by two Nobel prize winners and sent to 10,000 teachers and students. They refused to acknowledge the error or allow a link. The result is that the incorrect image is being drilled into thousands of students ... As you can see from the table, the number of cases is increasing every year, to the point that I can't keep up very well with the ones being reported to me!

The goal of the page is to stem the tide of this error. If we can't learn to fix something simple, how will we fix bigger problems?

So, with your permission, I would like to keep the original image and I would love to see and include a revised one!

Let's have fun with this!

In keeping with the tone of the web site, it is most fun to play around. This has resulted in some rather funny - and even scientifically interesting - exchanges, for example:

Flat DNA Images

Sometimes an artist will flatten DNA. That is, one cannot tell from the 2 dimensional image whether it is meant to twist to the left or to the right in 3 dimensions. The way to tell this is to look at the intersection points between the two strands. If you cannot distinguish which strand is on top, the image is effectively `flat'. In the figure to shown here, on the left is a left handed twist representation and on the right is a right handed twist. In the middle these are combined so that one cannot tell which direction the twist is, if any. The result is like a Necker cube (search for other sites) - you could read it either way. It is my policy to not include these on the page since one could consider it artistic license. (I created the figure with Xfig, a spectacularly precise drawing program.)

Tom Schneider
origin: 2000 January 11
updated: 2022 Jan 21 Use better link to xfig