Hi there- lurker here. I great enjoy reading Pinstripe Alley and it's mathematical analysis of things in between my breaks at... you guessed it, a biochemical research lab. We actually do testosterone measurements on serum samples (though not from baseball players). After the jump, you'll find a quick explanation as to why you should be totally outraged at the idiocy of Ryan Braun's situation.
The assay ("test to measure") for testosterone is fairly straightforward. You take the sample, centrifuge it if it's blood (skip this step if it's pee), and ...wait for it... FREEZE IT. We freeze it to keep the testosterone (and epitestosterone) molecules from being degraded due to either heat or enzymes. In fact, if you just left it lying around, the levels of testosterone and epitestosterone would be lower, although they would be proportional, so the ratio theoretically should be the same (depending on how long it was kept out). This doesn't happen because epitestosterone levels could fall to a level that is below the minimum signal threshold (IE there isn't enough to calculate a ratio) and the test pretty much fails.
So this investigator actually did the right thing in freezing it and sending it later. The testing protocol was, by my estimation, made by scientists- it's not stupid, it actually makes perfect sense to put it in your freezer instead of driving 50 miles and drop it off to let it sit in a questionably temperature controlled room. I'm baffled by the people that don't understand this (I'm looking at you, Shyam Das) and think that the investigator somehow broke protocol. In fact, he did everything exactly correctly. Except for putting a video tape on the sample for the 50 hours it was in his house. What an idiot.
Read your favorite protocol regarding this assay, but here is an awesome (according to me) article on sports drug testing and you get an added bonus of how people cheat without being caught. Read a comprehensivearticle here or an abstract here.
-Not Bill Nye