You know, I mean no offense to all my pharmacologist friends and readers, but. . .do y'all really know why all those things are in your buffers and solutions? I've been wrestling with this the last few days, trying to straighten out my "vial thirty-three" problem, and it's been interesting.
There's some reducing agent in there, naturally. Can't have those thiols turning into disulfides and balling up the protein, I understand - but does something bad happen if it's not in there? Generally, no one finds out, because, hey, why mess with it? And there's some EDTA, and some salt, and their function is? Well, as far as I can tell, they're also in there because they've sort of always been. Same goes for the squirt of detergent (Brij-35 or some such), and the tiny bit of bovine serum albumin, of all things. It's just part of the old-fashioned recipe from Grandma's Protein Kitchen.
Now, organic chemistry has a little of this, true, but it hasn't reached quite the Ancient Runestone levels of enzymology. We like to use tetrahydrofuran (THF) for a lot of organometallic reactions, for example, but at least we know that that's because THF is a good co-ordinator to metal cations. At least we don't have six other trace constituents in there that we always use whether we need 'em or not. Another example is how we tend to stick to good ol' ethyl acetate and hexane to run TLC plates, rather than look into other solvent combinations that might do a better job - probably because there are just too many of them to investigate, and EtOAc/hexane works well enough.
And that, I think, is the problem that the biologists face. Biochemical systems are tricky. They have way too many variables, which means that their degrees of freedom have to be reduced just to get anything to work. So all sorts of recipes and rules of thumb are handed down. Not all of them are optimal, but they're mostly decent and will allow you to get on with the project without wasting too much time. Especially in the early part of a project, an immediate 70% effectiveness is worth a lot more than a 98% that would take you a month of work to tweak up to.