Donna J. Nelson is a professor of organic chemistry at the University of Oklahoma with a CV that's over 31-pages long. One of the most recent entries? Science advisor to AMC's hit show about a chemistry teacher gone nutso, Breaking Bad.
So, how did Nelson land this dope (sorry) job? She saw an ad in Chemical & Engineering News, which is definitely where you advertise if you're looking for an expert to ensure accuracy when it comes to all the things Walter White has his dirty little nose stuck in.
The writers turn to her when they want to make sure they get the details right, and for the most part, it works out. Of course, it's not always perfect:
[W]hen Walt was teaching high school and there was a scene on alkenes. They asked is there anything that Walt would write on the board. I told them I could send a drawing of alkenes and that is indeed what’s on the board. The alkenes are missing a couple of hydrogens but otherwise they did a pretty good job of drawing them.
As for how good her meth cooking skills are — well, they're on par with Heisenberg's:
...I did one time make one compound with huge needles, similar to what they show in Breaking Bad. That was 9-Borabicyclo[3.3.1]nonane. Some people call it “banana borane.” I used that when I was a postdoc with H. C. Brown [a 1979 Nobel chemistry laureate] at Purdue. I was usually able to get it very, very pure just like Walt was able to get his very pure. If these large needles are really pure, they are colorless. But when I looked at them closely, it was almost as if they had a slight bluish tinge.
But don't get too excited/terrified, you can't actually learn to make meth just by watching the show. Breaking Bad's creator Vince Gilligan has DEA agents checking scripts to make sure of it. How very Hank of him.