Gel Filtration of glucans

[jdwalton]

I am trying to characterize a beta1,4-glucan product made in vitro. I think it is sticking irreversibly to the gel filtration column, which is a dextran/agarose type.

Any advice for how to block nonspecific interactions? I've tried salt up to 1 M NaCl and also ddH20. 8 M urea seems too viscous to try.

Jon Walton
MSU

[HW Mueller]

The glucan is a sugar polymer? You will salt it out with 1M NaCl, 4-6M urea should be sufficiently chaotropic. Also, salts below ~0.1M are just about all chaotropic, or a chaotropic salt at that or higher concentration might help. Is there a dissoiating group in your glucan?

[jdwalton]

Thanks for the advice. Today I am going to try 6 M Guanidine HCl, which seems less viscous than urea and Pharmacia says is safe to use on their column. If that doesn't work I'll try <0.1 M salt (e.g., 80 mM NaCl or 4 M urea.

I don't think our glucan has any dissociating groups other than hydroxyls. It might be attached to a protein.

Jon Walton

[HW Mueller]

I forgot the obvious above, namely organic modifiers, foremost alcohols, here, if allowed.