The Saga Continues
I may have been putting off this post perhaps because it is not as fun reporting as good news.
I went to APS a couple of months ago to collect data on the miracle crystals (see link above). Cory from Emerald Biosystems was able to swing by (at nearly midnight!) and mount then plunge the crystals. Despite the channels being narrow, the mounting process is easy and by adding the appropriate buffer after opening the card there is no need to rush. I then transfered and screened the crystals. The result…
Salt crystals…
The crystals had a number of different morphologies, but unfortunately they were all salt crystals.
Although I have seen many others have the fun of collecting on salt crystals this was my first time. If you haven’t had the experience it is like watching a unicorn die.
enrico
January 15th, 2010 at 1:58 AM #
Quoting Duncan McRee:
“There is nothing more exciting than the first diffraction photos from a new protein crystal. There is nothing more disappointing than to discover that the crystal is really salt!”
Sorry about that, I know what it means.
Cheers.
Stephen Curry
January 15th, 2010 at 3:39 AM #
Nice post – important to log the disappointments as well as the successes.
Thanks for the heads up on Emerald’s crystal card. Do you make a lot of use of it (in other words, does it justify the expense?)
Have recently been trying to think of ways to slow down the process of mounting crystals for cryo-cooling (esp. long, thin needles that need microfocus beamtime) so as to have time to get the crystal orientation in the loop right. Not got very far yet, but would appreciate any ideas…
Simon Higgins
January 15th, 2010 at 3:55 AM #
It’s happened to me before… It also reminds me… I used to work for an old-school prof. who insisted that we keep all the ‘mother liquors’ from reactions in case anything unexpected crystallised from them later. Now, when he worked in the lab in the ’60’s, on multi-gram syntheses of Pt metal complexes, this was fair enough, but we were working on milligram scales (platinum metals having hugely increased in price). He used to insist on examining the residues, left out in conical flasks on our benches, but we knew it was rather a waste of time as most of our compounds were air-sensitive anyway! One of my colleagues once added some sodium chloride crystals to such a flask. Imagine the Prof’s excitement. He had to be restrained from rushing off to the crystallographer there and then!
rpg
January 15th, 2010 at 5:31 AM #
Oh bad luck, mate. That brings back memories!
Sean
January 15th, 2010 at 10:51 PM #
@enrico: Great quote. It may have to make it over to the crystallography quote post
@Stephen: Emerald was generous enough to allow me to use their machine (The Plug Maker) and give me the card for free. So in my case, I can say the cost is justified
Unfortunately, I don’t know the pricing of the Plug Maker (it is not listed on their site), but am sure they would be willing to give you a quote. The Crystal Cards run $745 for 5.
I have not used these particular loops myself, but perhaps MicroLoops E by MiTeGen may help in mounting needle like crystals. As a side note, I was fully prepared to use your beamline talent should the crystals have iced up.
@Simon: Haha. A cruel justice at play
@rpg: Thanks for sympathies
Sili
January 16th, 2010 at 3:06 PM #
As a small molecule person, my disappointments have been less annoying (though occasionally harder to notice if one doesn’t check the UC). But nonetheless I feel your pain.
Stephen Curry
January 17th, 2010 at 11:08 AM #
Many thanks for the tip about the MiTeGen microloops – hadn’t seen them before.
Chris
February 12th, 2010 at 11:48 AM #
“like watching a unicorn die”
I know exactly how you feel. Nothing is more disappointing that finding out your crystal is salt.
Padayatti
September 3rd, 2010 at 11:55 AM #
Hi
I happen to see P212121.com blog.
nice and good job.
wondering how you decided the crystal image that you have up here is a salt? did you run an SDS PAGE?
some time back i had a protein crystal diffracted somewhat looked like this, later upon let it dry in cryo for 15 minutes turned out to be so protein and collected data sets on it. I got this drying out idea from an old acta d 60 2004 1413-16. It one time worked for me as well
Sean
September 6th, 2010 at 6:18 PM #
We shined some X-rays at it and based off of the diffraction pattern determined that it must be salt.