Colloid staining methods

The first introduction of gold and silver colloid staining methods dates back into the mid 20th century. Following decades of simple bio-assays based on deposition and aggregation of nano particles the signal transduction by metal nano clusters has... 

Colloidal gold. This is a useful label for both direct and indirect staining methods since it requires no further reagent additions. Gold probes may be readily seen by light microscopy when coupled with silver enhancement and in addition, being electron dense, offer excellent sensitivity for the electron microscope. 

Stains in the form of colloidal dispersions The need for highly sensitive detection methods for proteins after blotting (e.g., electroblotting, dot-blotting, slot blotting) applied to nitrocellulose or PYDF membranes drove scientists attention to develop new stains. It was discovered that the stains in the form of colloidal dispersions are suitable for such applications. The most commonly used colloidal stains are... 

Yamaguchi M, Kondo I. Immunoelectron microscopy of Proteus vulgaris by the plasma polymerization metal-extraction replica method differential staining of flagellar (H) and somatic (0) antigens by colloidal golds. J Electron Microsc 1989 38 382-388. 

Other in vitro methods include the determination of the weight needed to break the adhesion [41], the fluorescent probe [35], the flow channel [42], mechanical spectroscopy [43], the falling film [44], colloidal gold staining [45], viscometiy [46], the thumb test [47], the adhesion number [47], and electrical conductance [47]. 

The colloidal gold stain is the most sensitive membrane stain described here. As an alternative to commercially available colloidal gold stains, Moeremans et al. (1985) describe methods for preparing gold and iron solutions. 

Describes a method for preparation of colloidal metal stains. 

CBB provides a simple few-step method for protein visualization and offers detection of proteins down to 10 ng per spot (depending on gel thickness). New commercial colloidal CBB stains do provide a dynamic range of detection, with good compatibility with mass spectrometry for protein identification, but even these new dyes are not linear within the order of magnitude of protein levels found in the cell. 

Taban, C. H., and Cathieni, M. M. 1995. Microwave-aided binding of colloidal gold-protein-sub-stance P. In Immunogold-Silver Staining Principles, Methods, and Applications (M. A. Hayat, ed.), pp. 183-195. CRC Press, Boca Raton, FL. 

Ideally, the gel should have been stained with a Coomassie stain—preferably a colloidal Coomassie if detection sensitivity is an issue, e.g., (2,3), or one of the commercially available stains. This method is also compatible with Sypro stains (though an ultraviolet transilluminator will be required to visualize the protein bands or spots during excision). Standard silver stains are not compatible, but certain modified silver stains—e.g., (4), or one of the commercially available mass spectrometry compatible silver stains—can be used however, even these usually give inferior mass spectrometry data compared to Coomassie- or Sypro-stained gels. 

M54. Mowry, R. W., The special value of methods that color both acidic and vicinal hydroxyl groups in the histochemical study of mucins. With revised directions for the colloidal iron stain, the use of alcian blue G8X and their combinations with the periodic acid-Schiff reaction. Ann. N. Y. Acad. Set. 106, 402-423 (1963). 

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