February 27, 2016 at 12:39AM

Today I Learned: 1) RNAzol, a compound used for extracting RNA from cells and tissues, absorbs with a spectrum JUST SIMILAR enough to RNA to make one think it might just be RNA... don't be fooled by the ng/uL amounts, though, it's just contamination! 2) Speaking of RNAs, it seems that when preparing an RNA ladder for a gel, you should let it cool for more than 90 seconds on ice after melting it. I'm still not sure if it's important to use a long, cool melt. 3) EDTA is freaking hard to solubilize! I was setting up a protocol that called for 0.5 molar EDTA, which I didn't have. "That's fine", I thought to myself, "it's just a salt in water. I'll just whip together a solution in my 10 minute wait step". Thirty minutes later, I'm googling "dissolving EDTA" and reading all about the difficulties people have solubilizing it. Apparently it won't dissolve unless you raise the pH (usually with sodium hydroxide), which is hard because EDTA is a relatively strong acid. Even with the pH high enough, it usually takes heat, constant stirring, and patience. One of these days, I'll go ahead and make enough EDTA solution to last the lab until I'm done. Until then, I'll be either skipping EDTA or using TE buffer instead.