A DNA puzzle

Submitted by Sandra Porter on 10 July, 2007.
Science Blog

Okay, all of you biochemists and molecular biology types. I have a puzzle for you that I found by accident during a lecture. Yes, I was the one lecturing and the notes will be posted soon.

In the meantime, here's your puzzle: What's unusual about this pair of bases?

tags:

i-e3a9a2cc1675a74d231e553c53fc547b-basepair_puzzle.gif

(Those of you who attended our Chautauqua course - I know you probably know the answer - but don't answer, okay?)