Chemist/biologist slang for "precipitate" (as in "to precipitate from solution"). Can be used as a verb or a noun. Like most technical slang, it is used more often in the field than the formal term.
Occasionally mixed up with the different but related term "salt out".
n. That flask should be kept on heat until all the reactants are in to avoid premature crash out.
v. If you don't drop in more DMSO when you make the diluted solution, your compound's going to crash out.
v. "Salting out" a protein is increasing salt concentration in a solution until the desired protein crashes out.
