by Peter Nollert
December 24, 2009 15:00
The end of 2009 is near and it's time to clean up to make room for new and exciting projects in 2010. I'm just returning from the lab with a stack of protein crystallization trays to toss. Some of the crystallization experiments were prepared more than a year ago! There were two categories of crystallization trays that I dealt with:
1. Trays set up with protein that have never yielded any crystals at all
Should I keep them and hope that via slow desiccation or proteolytic cleavage protein crystals will eventually form? Nah! Everything that's older than 6 months must go. Gone they are. - I'm having second thoughts though, now that I'm writing this. I could open the crystallization chambers for a while and let the drops dry out just a little and then close them again. After all, protein crystallization by dehydration does work sometimes. Or move the trials to a different temperature? Or add chemotrypsin to the drops and create target fragments that crystallize.
Crystallizers' remorse setting in big time....
2. Trays set up with protein that have yielded crystals and structures
I could throw them out altogether. Crystals diffracted, structure is done. But, why not keep a few trays with crystals? You never know when a project 'comes back' - with the need to co-crystallize together with a small molecule ligand or protein partner. Even if the crystals don't diffract they may be useful and serve as seeds.
Pretty (Ammonium sulfate) crystals. These are the easy protein crystallization setups to give up on and throw out.
Phew! - that was easy, actually.
2010 here I come!
Peter