From Watson and Crick to today, our view of DNA - and a bit of fact checking
The above image on the left is from Watson and Crick’s famous 1953 paper, in which they first published their proposed structure of DNA. Watson and Crick used x-ray crystallography to image the DNA. It’s a technique that involves shooting x-rays at a crystal of your target molecule and then analyzing the diffraction pattern that results. Today, technology has improved so much so that a team from Italy gave us the right image, with unprecedented detail of the famous double helix using electron microscopy. I didn’t place the above images side by side for no reason. The progression from the left to the right represents the progression of the cutting edge of science imaging over the past 60+ years. We’ve come a long way, huh?
I must, however, include a note of caution. You probably heard about this story several weeks ago when it was first announced. The accomplishment is indeed amazing, but you might not know you weren’t quite given the whole truth. The authors of the paper claimed that they imaged a single thread of DNA strung between two silicon pillars. PZ Myers took one look at the image and called shenanigans. Since the width of the DNA and the distance between spirals is roughly equal, why is the image on the right so thick? Myers dug a bit deeper and found out that the image isn’t in fact a single strand but instead a cord of at least six strands of DNA, since a single strand is too unstable to be imaged in the current setup. Over at the Guardian, science blogger Stephen Curry rips into the reporting of the scientific finding.
The conclusion? The Italian team made an awesome advancement, but their findings were overhyped by sloppy science writing.