March 23, 2016 at 11:34PM

Today I Learned: 1) Oh reddit. Oh my. http://ift.tt/1q3bT9L 2) The cost of synthesizing a plasmid, de novo, from Transcriptic, is about $250-350. Synthesizing libraries of a few hundred parts will set you back several tens of thousands of dollars. I guess I should have seen that coming. 3) There's a cool way to sort molecules by size, whose name I forget, but it's some subset of size exclusion chromatography. Like any chromatogrpahy, the basic premise is that you run a liquid sample of mixed molecules through a column that causes some molecules to run faster than others, based on some chemical property of the molecule. In this method, it's size. The way the column works is that it's filled with large beads that are honeycombed with little holes. Liquid can flow between the beads, but also through the beads. Large molecules can't fit inside the pores in the beads, so they flow around the beads. This makes them flow relatively quickly through the column. Small molecules *can* enter the pores, but it's hard for them to get back out again, so they tend to flow relatively *slowly*. This goes against all the usual intuitions of size-based chromatography (or, for us molecular biologists, gel electrophoresis). Thanks Anders Knight!