Protein expression & purification techniques - overview of some common techniques & typical workflow

[@WynneTheresa]

Hi! Thank you for the video! I have some questions: 1. How long is the stability of the purified protein after flash freezing? 2. After harvesting the cell, how long is the stability of the cell pellet at -80? 3. By any chance, do you add beta-mercaptoethanol and PMSF to your buffer? I've read that these have to be added the buffer just prior to use. But if that's the case, if I have leftover buffers, I cannot reuse them again and should throw them away? Thank you so much.

[@thebumblingbiochemist]

1 completely depends on the protein. Some are way more stable than others. 2 is typically pretty long! I've done years, but could depend on protein again. 3. I always just remake. You can add to just a portion that you use. And keep higher concentration buffer stocks anyway, then dilute to working concentration (helps avoid growth of mold & stuff). Good luck!