Sir

I must start by saying that I am somewhat anal retentive (in other words I am a scientist), although I prefer the personality descriptor ‘analytical’. That said, I could not help but note that a chromosomal DNA duplex used to illustrate a recent News and Views article (Nature 427, 593; 2004) has a left-handed screw axis. I note the occurrence of these not-infrequent aberrations as a form of personal entertainment with perhaps a touch of masochism, as it annoys the hell out of me for some reason.

Anyway, this example was particularly noteworthy because of the Correspondence by Stanley Scher in the same issue (Nature 427, 584; 200410.1038/427584c) in which he rebuts an earlier comment by John Maddox about the Watson and Crick duplex structure being self-evident. Apparently it is not. It seems that even after 50 years and countless renderings of the famous B-form DNA duplex, people still get it wrong about 15% of the time (my non-peer-reviewed, unpublished and incomplete survey). I can only conclude that the structure and its correctness are anything but self-evident, at least as far as advertisers and scientific illustrators are concerned.

In fairness I must note that there is the outside chance that Figure 1 was depicting a rare and controversial chromosomal Z-DNA domain, but even so, the helical parameters are way off.