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Dec. 18th, 2003 07:09 pm![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
catsittingstillWell, today I successfully mounted two protein crystals all by myself :-). Well, I kept calling my boss, Chris, over to come and see that I had done the various stages correctly, but I did all the actual manipulation.
These crystals I mounted in what are called "capillary tubes"--glass tubes drawn out fine and thin. I was using a 0.2 millimeter tube (yes, two tenths of a millimeter wide) to suck the crystal into, then depositing it in a 0.3 millimeter tube (just big enough for the 0.2 mm tube to fit inside). The tubes are a bit longer than my finger, and look like a little glass funnel narrowing down to a little white hair.
In order to see what one is doing at all, it's necessary to use a microscope. Then it's like looking at plumbing--if plumbing were made out of glass, and shaking all over the place. I'm better at relaxing than I used to be (it helps reduce the trembling), and I also got good results from fastening down one capillary tube with little dabs of playdough, so I don't move it out of focus while I probe around in it with the other. (Yes, we protein crystallographers use playdough--in the little yellow tubs with the plastic lids. And I think it doesn't hold well enough--does anyone have any recommendations? I'm thinking about taking some of my sculpey to the lab to see if it's stickier.)
The crystals are beautiful--like little glass cubes, with perfectly sharp edges (though the edges get a bit blurred after I've messed with them for a while)--floating in the fluid they grow from (referred to as "mother liquor"). Only the change in refractive index makes them visible--at the right angle they flash into clarity. Once they're moved into place against the side of the 0.3 mm capillary, and the excess fluid is sucked away to leave them high and dry (well, damp, it's bad for a protein crystal to be dry), they can sometimes be seen even without the microscope--like one faint winter star trapped in the translucent white hair.
I'm so glad I didn't smash them
I was also introduced to the X-ray diffractometer. Unfortunately the latter was very much a "pudding, Alice; Alice, pudding--bring in the next course!" introduction, so I expect I will still have to have help with it before I can use it by myself. And I attended my first group meeting, where one of the lab's graduate students talked about his thesis project. (I think I have sprained my brain, trying to learn to fast. May I go home and put ice on it?)
And that was pretty much the sum total of my day. Whew.
These crystals I mounted in what are called "capillary tubes"--glass tubes drawn out fine and thin. I was using a 0.2 millimeter tube (yes, two tenths of a millimeter wide) to suck the crystal into, then depositing it in a 0.3 millimeter tube (just big enough for the 0.2 mm tube to fit inside). The tubes are a bit longer than my finger, and look like a little glass funnel narrowing down to a little white hair.
In order to see what one is doing at all, it's necessary to use a microscope. Then it's like looking at plumbing--if plumbing were made out of glass, and shaking all over the place. I'm better at relaxing than I used to be (it helps reduce the trembling), and I also got good results from fastening down one capillary tube with little dabs of playdough, so I don't move it out of focus while I probe around in it with the other. (Yes, we protein crystallographers use playdough--in the little yellow tubs with the plastic lids. And I think it doesn't hold well enough--does anyone have any recommendations? I'm thinking about taking some of my sculpey to the lab to see if it's stickier.)
The crystals are beautiful--like little glass cubes, with perfectly sharp edges (though the edges get a bit blurred after I've messed with them for a while)--floating in the fluid they grow from (referred to as "mother liquor"). Only the change in refractive index makes them visible--at the right angle they flash into clarity. Once they're moved into place against the side of the 0.3 mm capillary, and the excess fluid is sucked away to leave them high and dry (well, damp, it's bad for a protein crystal to be dry), they can sometimes be seen even without the microscope--like one faint winter star trapped in the translucent white hair.
I'm so glad I didn't smash them
I was also introduced to the X-ray diffractometer. Unfortunately the latter was very much a "pudding, Alice; Alice, pudding--bring in the next course!" introduction, so I expect I will still have to have help with it before I can use it by myself. And I attended my first group meeting, where one of the lab's graduate students talked about his thesis project. (I think I have sprained my brain, trying to learn to fast. May I go home and put ice on it?)
And that was pretty much the sum total of my day. Whew.
