The Left Handed DNA
Hall of Fame

- Tom Schneider
The Left handed DNA Hall of Fame has moved.
Please note the NEW LOCATION:


    version = 2.01 of leftyear1995.txt 2009 Sep 29

  1. The Trends in Biotechnology cover June 1990, Volume 8 No.6 shows an SEM image of a left-handed DNA with the words "Scanning Tunnelling Microscopy of Biomolecules". In the article itself ("Scanning tunnelling Microscopy in Biotechnology", P. G. Arscott and V. A. Bloomfield, page 153), fig 2 shows a left-handed DNA with a figure legend stating that it is "in the left-handed Z form". Yet on page iii is "Front Cover ... A single molecule of B-form DNA ..."
  2. The IBI 1990 Catalog cover two kinds of model, both left handed.
  3. Perkin Elmer Spring 1990 Biotechnology Catalog cover
  4. Bio-Rad Bio-Radiations No. 76, 1990, page 4, "DNA Preparation for Forensic Analysis" with a left-handed helix. To track the space invaders? "Image: Nelson L. Max".
  5. A Genosys advertisement in Trends in Biochemical Research 15(4) April 1990. "Some good things you have to wait for." (under a picture of wine and glasses) "Others you don't." (under a picture of left-handed DNA).
  6. "Logic of the Escherichia coli cell cycle", Richard D'Ari and Philippe Bouloc, cartoon in TIBS May 1990 15(5) 191-194.
  7. Clontech advertisement in Nucleic Acids Research 18(4) July 25, 1990. "we can offer you guaranteed quality and excellent service."
  8. Applied Biosystems meeting "Automating Molecular Biology: Tools and Techniques for the 90's", September 12, 1990, National Institutes of Health, Lipsett Amphitheatre, Bethesda, MD. This company makes the most popular DNA sequencing machine.
  9. Science 1990 Nov 9 issue had business reply cards to join membership in the American Association for the Advancement of Science. The card has the words: ' "I have to read SCIENCE every week" James D. Watson Nobel Laureate' above a left-handed DNA. This appeared in Science in two other formats, one on 1991 Aug 19. The original paper on the structure of DNA is:
    author = "J. D. Watson
     and F. H. C. Crick",
    title = "Molecular Structure of Nucleic Acids:
    A Structure for Deoxyribose Nucleic Acid",
    journal = "Nature",
    volume = "171",
    pages = "737-738",
    year = "1953"}
  10. Biochemistry book by C. K. Mathews and K. E. van Holde, The Benjamin / Cummings Publishing Company, Inc. Redwood City, California, ISBN 0-8053-5015-2, 1990. Page 923 shows RNA polymerases working on left handed DNA that somehow manages to switch over to right handed DNA elsewhere on a circular plasmid. This is a pretty clear example of an artist flipping a drawing over. This textbook drawing was meant to show how transcription can cause supercoiling. It shows two polymerases transcribing towards each other, but with opposite DNA twists. A student could become rather confused: the DNA as drawn would not become supercoiled by the transcription!
  11. Tessman Letter: Genosys Nature 14 June 1990, page xiii
  12. Tessman Letter: ZymoGenetics Science 15 June 1990, in the back
  13. Collaborative Research Science 15 June 1990, in the back
  14. Tessman Letter: Applied Biosystems Science 10 August 1990, p. 610
  15. Tessman Letter: Oncor Science 28 September 1990, p. 1475
  16. Tessman Letter: Clontech Nature 4 October 1990, p. xii
  17. Tessman Letter: Eppendorf Science 25 January 1991 (I have not confirmed this one.)
  18. In a Letter to Nature volume 350, 21 March 1991, page 184, Irwin Tessman (Department of Biological Sciences Purdue University West Lafayette IN 47907-1392) wrote about the ``Sinister change'' that had already by that time come about. He listed 6 advertisements in Nature 1 5 and Science, 2 3 4 6 a book and a Biotechnology center. Dr. Tessman is the earliest identified DNA Leftologist (people like myself who are puzzled and worried by this growing effect).
    as of 1998 Nov 19
  19. The MIT Technology Review "The Dark Side of the Genome" by Robert A. Weinberg, April 1991. On page 47 is a left-handed helix with with non-inverted letters on the bases next to a right-hand helix coming out of a bacterium. "Illustrations: James Yang", "Diagram: Bohdan D. Osyczka."
  20. The Washington Post cover of section on High Tech Careers, Monday, May 5, 1991.
  21. The Washington Post section on Science/Public Health, page A3, Monday, May 11, 1992. The figure shows left-handed smallpox DNA four times.
  22. Schleicher & Schuell flyer 1991 July 30. "Only One Purification Kit Can Do All This." There are innumerable left-hand DNAs shown.
  23. Promega advertisement in Biotechniques 12(2), February 1992. "We make the grade like no one else. HeLaScribe (TM) Nuclear Extract - in vitro Transcription Grade"
  24. EG&G Berthold advertisement in Biotechniques 12(2), February 1992. "Now, A Better Way to Measure Gene Expression..." This one is signed: "(c) Schilling '91" running along the left-hand helix, so the inversion could not have happened at the last minute.
  25. Oncogene Science, advertisement in Science 258, 13 November 1992.
  26. USB United States Biochemical, flyer for "Images Non-Isotropic Kits for Detection of Nucleci Acids and Proteins" 1992 December.
  27. Digene Diagnostics. Inc., 1992-1993 Catalog cover has 2 right handed and 2 left handed DNAs.
    as of 1999 Jan 15
  28. Ambion advertisement showing a machine transcribing left-handed DNA [1993 March].
  29. QIAGEN advertisement for a "Back to Basics" T-shirt [1993 Nov 3]
  30. Nature genetics conference: Human Genetics: Mapping the Future. 1st International Conference, April 1 & 2, 1993, Washington, DC. The symbol g twists to become a left-handed helix. (advertisement in Nature, 28 Jan 1993) Perhaps the date of the meeting explains it?
  31. Amersham Life Science, advertisement in Nature, 28 Jan 1993. Many little DNA drawings, some are left handed.
  32. USB United States Biochemical, advertisement in Nature, 28 Jan 1993.
  33. Promega catalog cover of 1993/94. On the cover is written: "Revolutions in Science" and shows a picture of a left handed DNA strand with a photo of Oswald Avery in the background. What a revolution in science!! I wonder what they are hinting at? Anyway, to top this, the start of chapter four also shows another picture of left handed DNA. (Thanks to: Nico Gey van Pittius, Department of Medical Biochemistry and Physiology, Faculty of Medicine, Tygerberg, 7505, South Africa, Tel : +27-21-938 9402/7, +27-82-896 8949, Fax : +27-21-938 9476, E-mail: for finding and scanning the image, and for some of the description.) (Click on this cropped image for the complete cover. A closeup of this pretty figure is also available). as of 1999 March 4

  34. Time January 17, 1994. "Genetics: The future is now". The cover shows a picture of a spread out person with a huge left handed DNA embedded in his chest and abdomen. They refused to allow the cover to be put on this web site! (Thanks to Irwin Tessman, Department of Biological Sciences Purdue University West Lafayette IN 47907-1392. for scanning and sending the jpeg to me.)
    as of 1998 Nov 24
  35. R&D Magazine, April 1994. "ECL Detection Method Speeds Human Genome Mapping Project" pages 32-33 by Howard Goldner. "For more information: Shaf Yousaf, Amersham Life Science".
    I sent email to the editor, Robert Cassidy and he acknowledged the error.
  36. Nature Volume 372 No 6501 3 November 1994. The cover shows Darwin knitting a DNA strand. The end of the strand is right handed, but it switches to left handed further up. The cover was prepared in celebration of 125 years of Nature. The lead article is entitled "Frontiers of Ignorance".
  37. A book by Julie Chen on DNA teaches artists how to do it backwards: Double Helix: An Essential Component of All Living Matter, Berkeley, California, 1994
    as of 1998 Nov 19. 2002 Mar 6:

  38. "Make your own DNA", Thoki Yen shows how to make a lovely (left handed) DNA model by origami. TIBS February 1995 20(2) page 94.
    This was pointed out by Sean Eddy on a bionet news group. (Thanks to Alex Bateman MRC Laboratory of Molecular Biology,, Phone: (01223) 402479, for alerting me. Search for "DNA" on his site for an entire discussion.) 2002 March 6: Unfortunately the original link is broken.
  39. Science volume 269, 28 July 1995, page 468. According to the figure on this page, a new strain of the bacterium Haemophilus influenzae, known to cause ear infections and meningitis, has been found that has left handed DNA. How it is capable of infecting people with right handed DNA is not understood.
  40. Pharmacia Biotech advertisement in BioDirect August 1995 issue 5 volume 1 page 11 shows the cover of "Products for the Purification of [Lefthanded?] Nucleic Acids".
  41. Science volume 270, 13 October 1995, page 252. The article has a figure showing "The yeast a1/alpha2 repressor bound to [left-handed] DNA."
  42. Epicentre Technologies, advertisement in Science volume 270, 24 November 1995. "Now there's a better choice for transgenic DNA packaging. MutaPlax (TM) Transgenic DNA Packaging System ... only from Epicentre."
    To their credit, they acknowledged the error by email.
  43. 1995 NIH RESEARCH FESTIVAL Symposia, workshops and posters, September 18-22. "Cover Design: Artist's rendition of the DNA molecule, courtesy of the National Institute of Aging." WWW link (no image).
  44. H. A. Lim and C. R. Cantor book:
    Bioinformatics & Genome Research:
    Proceedings of the Third International
    Florida State Conference Center,
    Tallahassee, Florida,
    1-4 June 1994.
    World Scientific, Singapore.
    publication date: Sept 1995
    On the cover there is a computer chip with both left and right handed DNA emerging from it.
  45. R&D Magazine, November 1995 cover.
    To their credit, they acknowledged the error in the January 1996 issue (page 11).
  46. The cover of the 1995 Lab Manual Source Book from Cold Spring Harbor Laboratory Press (now the The BioSupplyNet Source Book) shows a lovely yellow left handed DNA.
    as of 1999 January 28

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!

1997 and 1998 were bumper crop years
and 1999 beat them more than 2 fold. 2000 was a record year, thanks to help from friends around the world (60 of the 97 cases, 63%!). 2001 exceeded even that record! 2002 was lower - are we making headway?

Year Number of Left Handed DNAs
1964 1
... -
~1980 2
1978 1
1982 1
1983 2
... -
1989 3
1990 16 (5 from the Tessman letter)
1991 6
1992 5
1993 6
1994 4
1995 9
1996 31
1997 37
1998 37
1999 77
2000 97
2001 105
2002 57
2003 55
2004 55
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 5 (images under Fair Use copyright policy)
2018 7 (images under Fair Use copyright policy)
2019 15 (images under Fair Use copyright policy)
2020 13 (images under Fair Use copyright policy)
2021 7 (images under Fair Use copyright policy)
2022 10 (images under Fair Use copyright policy)
2023 1 (images under Fair Use copyright policy)
All 868

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blue snow drift curve
Tom Schneider

updated: 2023Sep20_18:45:31

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