Protein Visualization

Several methods have been described to detect protein spots after 2D-PAGE. These methods use reactants such as Coomassie Brilliant Blue R-250, Amido Black, Ponceau S, Fast Green, negative staining, silver staining, fluorescein and radioisotopes. The two most popular approaches are Coomassie Brilliant Blue R-250 and silver staining. A good stoichiometric relationship has been documented between protein abundance and integrated optical density of protein spots for Coomassie Brilliant Blue R-250. The silver staining methods are more sensitive than those using Coomassie Blue and can detect as little as 1-4 ng of proteins. Several methods of silver staining of proteins have been described, with the most rapid ones being usually less sensitive and less reproducible than the more time-consuming ones. Among the latter methods, those using silver-diamine complex give the most uniform sensitivity. However, they require special home-made gels and cannot be applied to several electrophoretic systems. For these reasons, protocols based on silver nitrate are of more general use and are favoured. A variety of systems using different metal cations (K+, Cu2 +, Zn2 +) has been

Figure 2 Microheterogeneity of proteins. 2D gel of a cryoprecipitate containing fibrinogen (cryofibrinogen). A, albumin; AT, ar antitrypsin; T, transferrin; H, haptoglobin p chain; A-1, apolipoprotein A-1; Fa, fibrinogen a chain; Fp, fibrinogen p chain; Fy, fibrinogen y chain; Fy', extend fibrinogen y chain. Unknown protein spots are shown by arrowheads. All major identified proteins present charge microheterogeneities. First dimension: immobilized pH gradient.

Figure 2 Microheterogeneity of proteins. 2D gel of a cryoprecipitate containing fibrinogen (cryofibrinogen). A, albumin; AT, ar antitrypsin; T, transferrin; H, haptoglobin p chain; A-1, apolipoprotein A-1; Fa, fibrinogen a chain; Fp, fibrinogen p chain; Fy, fibrinogen y chain; Fy', extend fibrinogen y chain. Unknown protein spots are shown by arrowheads. All major identified proteins present charge microheterogeneities. First dimension: immobilized pH gradient.

developed to stain SDS-PAGE separated proteins without the need for fixative, organic dye or chemical modifier. SDS proteins stain negatively upon gel treatment with solutions of heavy metal salts. The zinc imidazolate reverse-staining method offers the advantage of combining good sensitivity, rapidity and reversible interaction. Furthermore, the zinc imidazolate reverse-staining method can be used in situations where Coomassie Brilliant Blue R-250 or silver staining is inappropriate or fail to produce detection of the polypeptides of interest.

Solar Panel Basics

Solar Panel Basics

Global warming is a huge problem which will significantly affect every country in the world. Many people all over the world are trying to do whatever they can to help combat the effects of global warming. One of the ways that people can fight global warming is to reduce their dependence on non-renewable energy sources like oil and petroleum based products.

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