Colloidal Blue

Amanda Nouwens anouwens at
Mon Mar 13 16:31:16 EST 2000

Dear David,

I use colloidal coomassie all the time:

17% w/v ammonium sulphate
3% v/v ortho-phosphoric acid.
34% methanol
0.1% w/v G-250

Add the ammonium sulphate, methanol and phosphoric acid to the water. It 
may take some time to dissolve the ammonium sulphate (try heating and 
stirring or sonicating), but it is important to dissolve all of the 
reagents *before* adding the G-250.

The stain will bind preferentially to the proteins, not the gel, so there 
is limited background staining.  I use 1% acetic acid to remove what 
background staining is present though.  For best results, leave the gel in 
stain for up to 3 days.  It looks even better (fainter spots/bands 
enhanced) if you stain-destain-stain again.  But this also increases 
methylation of the proteins.

Let me know if you require other details.


Amanda Nouwens.

>I was wondering if anybody could help me with a "recipe" for
>making up Collodial Blue (Comassie G-250) solution for
>staining SDS-PAGE gels.  Do you just make it up in water?,
>and if so what sort of concentration?
>Any help would be appreciated

Amanda Nouwens
Australian Proteome Analysis Facility (APAF)
Level 4, Building F7B
Macquarie University
Sydney, NSW  2109
Tel: 61 2 9850 6209 (office)
Tel: 61 2 9850 6255 (lab)
Mob: 0417 237 457
Fax: 61 2 9850 6200


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