(no subject)

[catsittingstill]

You may remember that we're going to the synchrotron in the middle of March. The x-rays at the synchrotron are so powerful that instead of taking days to analyze a crystal, as we do with the in-house (actually it's in the basement--these machines often end up in the basement because they're very heavy and because they need to be where there's very little vibration) we can take a full data set in an hour or so. This is great--but we have about 20 hours to fill, so we need lots of crystals.

You may remember that we finally figured out how to get good diffraction from the crystals I'm working on, by adding extra salt (or maybe some glycine--it turns out we added both and now we don't know which made the difference, but with luck we can sort that out by synchrotron time). The boss was very psyched.

Now he wants crystals of a seleno-methionine derivative of this protein by synchrotron time. I don't have time to explain this right now--but it involves moving the gene for the protein into a different bacterium, getting the bacterium to make lots of the protein, breaking up the bacteria and purifying the protein, then coaxing the protein to crystallize. I've laid out the potential schedule and it could work. Barely. Provided nothing goes wrong.

Those of you who have worked in science (hi tnatj!) will have some idea of the shivers that run down my spine as I consider the last sentence.



I'm still working on improvising to chord maps with the mandolin. "Rosin the bow" is a nice simple song, if not the sort of jazz song normally used for this kind of thing. I'm having fun and starting to incorporate some fast runs and stuff, but they're just runs--not all that melodic. I'm pretty sure my teacher is doing something fancier.

Comments

Hee!

[tnatj.livejournal.com]

I've laid out the potential schedule and it could work. Barely. Provided nothing goes wrong.

When I was a child (I was a child once) I went to a local winter sports park called Echo Valley.

Now the feeling I got on projects like this (with a hard deadline) has always been like the feeling I'd gotten when tobogganing many decades ago there:

With older children you are piled onto a highly polished laminated assemblage of wood. Of course, being small, you are placed right up front, behind the curl.

"Hold on tight!" someone says. Hands reach down to make sure your hands are inside the bounds of the toboggan, your mittens firmly holding the guide ropes. Safety check finished, the handler slides the long thing, packed with children, to the run. At the top of the toboggan run, you look down at the drop.

It is forever. You sit suspended over the drop, beyond the pivot point. And nothing happens. And then the toboggan handler tips the half-dozen of you forward.

At the bottom the flying ice crystals settle on your snow suit.

Now you must scramble to get out of the run before the next toboggan is scheduled to come sliding down after you. It is, after all, coming from a different drop-gate, and someone mentioned that the handlers don't always coordinate their timing. Plus, you know this one has grown-ups in it -- well, high-school kids -- and is certain to travel farther.

So you pile out in a hurry, slipping on the slick ice of the track. Two of the older children frantically pull at the wooden conveyance, and they do work it out onto the snow barely in time. Fortunately, nothing went wrong.

That time.

Good luck, Cat!

[randwolf.livejournal.com]

"Provided nothing goes wrong."

Have you considered sacrifices to the gods of protein crystalization?

Re: Hee!

[catsittingstill.livejournal.com]

:-) Thanks.

Re:

[catsittingstill.livejournal.com]

I'm not sure what would be appropriate.

[(Anonymous)]

On occasion, the crystallographers here at the Medical College of WI (http://www.mcw.edu) want me to do N-terminal sequencing on one of their proteins, just to be absolutely sure it is what they think it is. They are my favorite protein sequencing customers, because when they say they only have a small amount of protein, they mean an amount so large you can actually see it with the unaided eye. Tons. Well, hundreds of micrograms.

Michael Pereckas
mspland.com (http://www.mspland.com/)

[catsittingstill.livejournal.com]

:-) Hundreds of micrograms. Hmm. Well, that's not really enough to do a full crystallization trial, is it? As a matter of fact, that's usually what I have left over after a crystallization trial. You mean you can do something useful with that little bit of protein? Cool.

[(Anonymous)]

I'll ask what the concentration of their solution is and they'll say that they're not sure, they just dissolved a tiny crystal for me. This is my cue to begin the eye-roll. "High," is pretty much what it comes down to. The NMR gang here also has a different idea of "lots" than I do.

The sequencer is the less sensitive approach. You need maybe 10 pmol. A good strong coomassie-stained band or two. By tryptic digest and mass spectrometry we can identify a silver-stained band. One picomole is lots.

Michael