More Stupid AFM Tricks

On the subject of fun things to do with your AFM: A recent paper in Science on using an AFM for nano-assembly of DNA on surfaces. The authors used an AFM tip coated with DNA to pick up up complementary DNAs from one region of a surface and deliver them to another region patterned with yet more complementary DNAs. By tailoring the lengths of the complementary regions, this allowed them to essentially pick up and drop off DNA strands into arbitrary locations with nanometric precision. This presumably is another stepping stone on the way to making teeny-weeny machines of some sort, but I don't quite see how.

I was also reminded of a recent discussion we had on single-molecule NMR. It was suggested by somebody that this had never been done, but I actually presented an article on this for journal club some years ago in which this was done using a magnetic AFM tip. My paper journal-club file from grad school seems to have disappeared, but some dedicated Googling turned it up. Of course, it took them 13 hours to image a single spin in a chunk of glass, so we're not going to be using this to make biological measurements anytime soon.