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Chemistry Forums for Students => Undergraduate General Chemistry Forum => Topic started by: pulseultra on February 22, 2011, 04:40:18 PM

Title: Advice On Making A Solution for Protein Extraction
Post by: pulseultra on February 22, 2011, 04:40:18 PM
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..
Title: Re: Advice On Making A Solution for Protein Extraction
Post by: enahs on February 22, 2011, 05:07:03 PM
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.
Title: Re: Advice On Making A Solution for Protein Extraction
Post by: pulseultra on February 22, 2011, 05:36:27 PM
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
Title: Re: Advice On Making A Solution for Protein Extraction
Post by: pulseultra on February 22, 2011, 05:57:41 PM
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..