July 11, 2016 at 01:13AM

Today I Learned: 1) When fingers and toes wrinkle in water, that's not osmosis. It's actually an active reduction in extremity volume caused by constriction of blood vessels in response to the sensation of water. If you cut the nerves to an extremity, it will no longer wrinkle in water. There's some evidence that this may be an adaptation to help grasp things better in water -- it turns out that although wrinkles do nothing noticably useful in air, it makes gripping objects underwater easier. Personally, I'd say it's just as likely that it's an adaptation to minimize heat loss by reducing blood flow to extremities. Or maybe it's both. OR MAYBE I SHOULDN'T BE SO TELEOLOGICAL. 2) Antibodies are big! Antibodies can come in a lot of sizes, actually, but a typical one is between 100 kD (100,000 Daltons) and several hundred kD. For a protein, that's quite large! Somehow I had it in my head that antibodies were tiny little proteins. Why did I think that? 3) Most (>75%) of the surface area in a 96-well plate is the well sides, not the bottom. Credit for this fact, and the second one, goes to Erik Jue.