After precipitation, the attached ELP can be clipped off from the other protein and used again, he said. What remains is the purified protein of interest. All you do is add heat or pour in some salt, use a centrifuge and collect. It's a very cheap thing. There's not much cost in heating a solution 5 degrees.
Common salt is pretty cheap.
And centrifuges are pretty cheap. More economical and technically simple methods for the purification of soluble proteins are therefore desirable. In this article the Duke team evaluated just two proteins. It's very logical why we picked them. They are thoroughly different in their solubility properties.