Left Handed DNA
As listed in
13 November 1998: 282 (5392): 1223,
NetWatch Hot Picks
- Tom Schneider,
molecular information theorist
On your cover a very rare sight,
As shown in the figures to the left and right, most DNA of living things on the earth twists as a "right-hand screw". This is the same direction as a regular wood or metal screw. Many artists will flip a picture of DNA over and reverse the twist. Although left-handed Z-DNA has been demonstrated by X-ray crystallography and scanning tunnel microscopy (STM), it only recently was established that it occurs in vivo (Schwartz et al Science 1999 Jun 11;284(5421):1841-5, New York Times, June 29, 1999).
for this figure.
See the Right Handed DNA Hall of Fame and my home page on molecular information theory too!
For your first visit to the Left Handed Hall of Fame page I suggest that you follow the story over all of the years. After that you can look at each year individually from the table below. Note: just because a year has gone by does not mean we haven't found more examples for that year!
|Year||Number of Left Handed DNAs|
|1990||16 (5 from the Tessman letter)|
|2005||44 (minimizing images)|
|2006||17 (minimizing images)|
|2007||26 (no images, sorry)|
|2008||16 (no images, sorry)|
|2009||23 (no images, sorry)|
|2010||26 (no images, sorry)|
|2011||11 (only 2 images, sorry)|
|2012||11 (only rare images, sorry)|
|2013||12 (only rare images, sorry)|
|2014||12 (only rare images, sorry)|
|2015||3 (images under Fair Use copyright policy)|
|2016||2 (images under Fair Use copyright policy)|
|2017||1 (images under Fair Use copyright policy)|
version = 1.01 of leftyear2017.txt 2017 Mar 01
Our Story So Far:
The story line, if you have not had time to
previous 790 or so entries
(!) is my slow realization that earth
is being invaded by left handed DNA people ...
Please enjoy a visit to my work web site and read my papers.
None of the statements on this page are intended to endorse or favor any product over other equivalent products on the market.
When a source can be identified, permission has been requested to reproduce all graphics. If someone knows who made that cute mouse (which I picked up from somewhere on the net), please tell me.
It helps if you check through the previous entries to see if you have been scooped, as I do not repeat (even for really egregious cases). To do this please use the Left Handed DNA Google search engine. ( as of 2003 Feb 25)
DO NOT SEND IMAGES BY EMAIL!!! If you would like to contribute examples that are on the web, please send me precise evidence that documents the case, along with all reference materials that are available. Precise web pointers are appreciated as it saves me time. If there is an image on the web just tell me where it is, please NEVER send me images that I can get from the web! I have to check them anyway and I use wget to grab them. Let me put that another way: I cannot use graphics sent to me. I only use ones I can verify from the web.
Finally, PLEASE DO NOT SEND ME DOC FILES!
Also please indicate whether you would like to be acknowledged on this page. Your name will be listed with your email address if you do not tell me. Since I don't want to have to recall previous rules for people, please tell me how you would like to be listed each time. You may pick an alias such as Gorilla Guerilla (which is already taken).
Web Sites: For web sites, it helps a lot if you email to me three URLs:
Printed Sources: If you would like to contribute examples that are not on the web, please send me hard physical evidence that documents the case, along with all reference materials that are available. The simplest address for sending physical evidence is:
Tom Schneiderbut please contact me by email first to save time and effort. DO NOT SEND IMAGES BY EMAIL!!!
Frederick, MD 21702
Books: For books please send a photocopy of:
|date (this is a "hits-tory" ;-)||number of visits|
|2000 Apr 20||8910|
|2000 Apr 25||9002|
|2000 Apr 26||9058|
|2000 Jul 24||11091|
|2000 Jul 25||11146|
|2000 Nov 3||14152|
|2000 Dec 20||15737|
|2001 Feb 10||17495|
|2001 May 8||20736|
|2001 May 21||21125|
|2002 Mar 3||28992|
|2003 Jan 30||41368|
origin: 1996 Feb 14
split to multiple pages: 1999 March 27
version = 2.45 of leftmaintail.html 2011 Sep 22