Dear all,

First of all I have to say that I am not really experienced with cells and proteins isolation.

My question is that I wanna isolated Histone H1 from a type of cells. There are a lot of reports, but all of them used acidic conditions (perchlorid acid, sulfuric acid, trichloroacetic acid...) and thats something that I would like to avoid. In some of the cases I understand that such conditions are used to precipitate the proteins and in others I guess that are to break/lyse the cell membrane nucleus.

Are u aware of any method to isolate proteins from the nucleus avoiding acidic conditions?

And second question, why such acids are being used to isolated such proteins (in case that my previous afirmations are wrong)?

Thanks very much!

Lysing the cells is usually done mechanically. The acids may or may not have something to do with separating the histones from DNA, but I am just speculating. Do you have some good books on protein purification (Scopes, Suelter, etc.)? Those are extremely valuable.

Acidic extraction of histones is mostly done to precipitate proteins and components other than histones as they are quite soluble under low pH (often followed by a TCA precipitation). I.e. it is used to enrich histones.

 

Lysis is independent of it and depends largely of the type of cells (though sonication and, as mentioned, mechanic lysis are among the most universal principles).

There are quite a few protocols out there fore nuclear proteins and I believe high-salt extraction has also been employed for histones successfully (see von Holt et al. Methods Enzymol 1989)