[pulseultra]

Hey guys, I've been trying to make a solution for protein extraction, as per the specifications from a Chinese article.

The solution is to be composed of 6M Guanidine-HCl, 0.5M EDTA, 0.1M Tris at pH 7.4.
Tris dissolves no prob.
EDTA dissolves at pH 8 and above.
I've made a 6M Guanidine-HCl solution before.

But the EDTA and Guanidine-HCl together REFUSE to dissolve.

Anyone ever made anything similar?

Thanks in advance for an insight..

[enahs]

EDTA dissolves below pH 8, that is for sure.
What form of EDTA are you using? (disodium, tetrasodium, potassium, etc).


But, I gotta be honest, I am no biochemst, but I do not see a 0.1M buffer having enough buffer capacity to handle a significant amount of a 6M HCl salt...what volumes of the different species are we talking here.

[pulseultra]

Hey enahs/shane,

I've tried both with disodium and tetrasodium EDTA.

I'm not worried about Tris's buffering capacity. As you pointed you, it is VERY fragile, but I've succeeding in preparing a 6 M Guanidine-HCl, 0.1M Tris at pH 7.4.

Were you hinting at a common ion effect? I've added quite a bit of sodium hydroxide as well... I think I might have to do some common ion effect calculations...

Thanks again

[pulseultra]

Sorry, as for the volumes of the different species,

i've used Tris hydroxymethylaminomethane, tried both di- and tetra- sodium EDTA and Guanidine HCl.

I might as well ask if anyone has any other buffer suggestions for protein extraction from bone..