it's all about getting fat juicy crystals. but protein forming crystal is still surrounded by lots of "mystique and aura", so many facotrs. of course it's not earthquake prediction, but still... many times you cross your fingers. you eat a delicious cuisine, and you just say lucky, next time no guarantee it will duplicate. a kind hearted mentor will give students several proteins to work on , otherwise the poor student could be stuck with one naughty protein and never get phd!

usually you can use same or similar methods for the same family of proteins, but many times you will need to devise new ways for different type protein.

there's a long time rumor scientists wrote very briefly about their methods part on grwoing crystal, to keep the edge over fellow competitors.

more than 10 years ago, many theoretical scientists both in china and abroad predict the quick death of protein crystallography: structure prediciton is going to solve all problems, much to the dismay of crystal growers.... but now we can safely say the prediction is over optimistic, crystal structure researchers job are needed for a long foreseeable future. and their hardworkign will be best rewarded: if it's a novel class protein structure, you bet the paper will be in top tier journal.