June 22, 2016 at 02:17AM

Today I Learned: 1) You can totally use a PCR clean-up kit on salty plasmids. 2) Beavers have a scent gland called a castor sac, which is used to mark territory. Very rarely, castor sac excretions are used as "natural flavoring" in place of vanilla. 3) ...so there are supposedly these things called "stationary promoters", which are DNA motifs that turn on gene expression when bacteria are in stationary phase, which is when they're really densely grown and heavily nutrient-limited. Today I learned that those promoters may not be so "stationary phase" after all... I got to see some data that sure looks like the standard stationary phase promoters (consensus and variant binding sites for sigma-38, for those interested) actually turn on in late log phase, when a culture is just about to go into stationary phase. Once the cells are stationary, they no longer seem to continue producing protein... though whether that's because the promoter is off or because they run out of resources or they're degrading stuff really fast and hit steady state, I still don't know.