I had a moment of terror yesterday. I was transferring the sketch of my next painting to the watercolor paper, using some old carbon paper gifted to me by my grandfather many years ago. Half-way through drawing over one of the hundreds of tiny RNA double helices, I noticed it was left-handed. How embarrassing. I panicked, of course, and quickly scanned the rest of the sketch. I had previously looked at a few structures of little RNA oligos at the RCSB PDB, to get the sizes right, but little errors like this can creep in while refining sketch after sketch if you’re not careful. Fortunately I found, after I calmed down a bit, that the rest of the sketch was fine, so I took out my eraser and fixed the offending helix. If I had made the error throughout, I suppose I could have flipped the whole sketch over and transferred it from the back. Or maybe tried to convince everyone that primordial RNA was in the Z-form?