Here's an esoteric rant for you: I can't friggin' find a test-tube rack that holds either 15mL or 50mL Falcon tubes, and it's pissing me off because I know I'm not the only person in the world who would use such racks.
These are Falcon tubes:The BD website describes these things as the "workhorse" of the Life Sciences lab... everybody I know uses hundreds of these things, for all sorts of purposes. They don't goddam fit in standard test-tube racks, because of those big, fat screw-on caps. Normal test-tube racks have the positions arranged in a square layout, with very thin barriers between the positions. The lids on these tubes overhang the edges of the positions, and two tubes next to each other squeeze against or on top of each other. It's annoying. Plus, the bigger size is apparently much larger than any other tube that people would be using more than one or two of at a time, so standard test-tube racks usually don't even have positions in them large enough to squeeze these guys into.
You can order these tubes in styrofoam racks, which adds a bit to the price when buying them, and because the tubes are disposable most of the time we don't bother - we just buy them in big bags, sans racks. The styrofoam racks tend to fall apart pretty quickly in any case, and some websites say "do not freeze in racks" without frickin' explaining why. Argh!
I've spent too much time today, in the blocks between the end of something and waiting for somebody else so I can move onto the next task, trying to track down a rack solution for our hundreds of Falcon tubes. The only thing I've found is a hideously expensive coated-wire rack that holds 8, 16, or 36 of these big tubes - for about $80 for the largest. At any given time, I've got between 200 and 500 Falcon tubes in use, distributed between a couple of freezers and whatever random patch of bench space I happen to be using. At the moment, all of my 50mL tubes are just jumbled together in the freezer, completely disorganized, and my 400 or so 15mL tubes are squeezed awkwardly into about a dozen unsuitable racks. It's annoying, I need a better system.
Why can't I buy a cheap plastic rack in hexagon arrangement that will fit in my freezer?