My intrepid benchmate had a bit of a rough time today. Nothing, she lamented, seemed to be working. She came in to an incubator full of agar plates with nothing growing on them, which apparently set the tone for the rest of the day, unfolding as it did with various minor disasters and pesky obstacles. Nothing devastating — just enough to annoy.

But she was most concerned about her blank plates: seven entirely different supercoiled plasmids, all zapped into expensive competent bugs from a reputable company starting with S. What, she speculated, might have gone wrong? We talked through her protocol: the bugs were working fine, because I’d used them myself only a few days ago. Her transformation manipulations were text-book, and the DNA itself was above reproach. We were both stumped.

But then she slowly reached for her lab notebook and muttered, “Hang on a minute.” A few moments of page shuffling and plate examination ensued. And then:

“Oh, damn.”

Somehow, she’d plated the two kanamycin-resistant bugs on ampicillin plates, and the five ampicillin-resistant bugs on kanamycin.


But fortunately, there was a happy ending. She realized that the tubes full of bugs were still somewhere in the bin underneath our bench. Scrabbling through the trash, gloves and pipettes flying every which way, she finally managed to find all seven tubes and was able to restreak all of her transformed cultures onto fresh plates. (I told her if she really wanted to go for it, she should re-use the plates that nothing had grown on. But she wasn’t too impressed with that idea.)

The purists may frown, but I’ll bet they grow. Stay tuned.