IgG purification - amonium precipitation method (Aug/03/2007 )

hello very one,
i am purifying IgG from rabbit blood (for specific antigen).i am using ammonium precipitation method. in this method v r using ammonium sulphate.

i need to know why v have to use ammonium sulphate why not any other salt.if can or if cant wht is the reason.

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hi alie,
ammonium sulfate precipitates proteins by absorbing the water around the proteins. so in this method the hydrophobic patches on the surface of the protein interact with each other because of the removal of water and hence precipitation happens. above all there is no denaturation of the proteins by this method of precipitation. and why only this salt? even i don't have a perfect answer but i think it is because ammonium sulfate is a weak salt and dissociates less so that the percentage of salt to be added can be controlled.
but i am not sure of this.
bye

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as suggested high water binding capacity to precipitate but without denaturizing the proteins; sulphate supports to keep the native structure of precipitated proteins

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Thank you very much leelaram and bearer

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Why you don´t use Protein G column to purifiy IgG?

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thank you,moljul
i will.
thank u

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