[Protein-analysis] Re: Silver staining

Andreas Giessauf andreas.giessauf at uni-graz.at
Mon Aug 29 03:48:43 EST 2005

Chris B. schrieb:
> Hello,
> I need to stain polylisine - free and conjugated with peptide. Coomasie
> Brillant Blue fails with free polylysine and - for my suprise - so does
> silver.
> I'm using silver staining method from Amersham Technical Manual (as it say -
> based on Heukeshoven and Dernick 1985) but they do not describe which
> aminoacids are essential for detection.
> Any help?
> Regards,
> Chris B.
    I used already Ag staining method described by Blum et al.

    Electrophoresis 8 (1987) 93-99 for protein staining.

     Also, this autor didn't describe which residues are necessary.

     But there are just two possibilities how the method works:

     (1) Ag+ from the fixing solution is reduced to Ag (colloid)

     (2) Ag+ reacts with free -SH groups and forms an Ag-S-R complex

      In the first case there must be amino acid residues present

      that can be oxidized by Ag+ (cysteines and others).

      In the second case there must be amino acid residues present

      that can form sulfides with Ag+-salts (cysteines are the only


				Best regards,

					Andreas Giessauf

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