Scanning electrochemical microscopy as a readout tool for protein electrophoresis.
Scanning electrochemical microscopy (SECM) was used to image silver-stained proteins on a poly(vinylidene difluoride) membrane. The method is based on measuring the current at a scanning microelectrode in the feedback mode. The electrochemical feedback is caused by the redox-mediated etching of the isolated 5 - 10-nm-diameter silver nanoparticles formed during the staining process. Several parameters, such as the redox mediator and the staining protocol, were optimized to ensure a high resolution and a low detection limit, i.e., 0.5 ng of bovine serum albumin (4 x 10(-14) mol) distributed on an area of 1 mm(2) (4 x 10(-16) mol x cm(-2)). Images of beta-lactoglobulin A and myoglobin bands after gel electrophoretic separation and electroblotting were obtained in order to demonstrate that SECM can be employed as a sensitive and quantitative readout method for detection of proteins after gel electrophoresis. An additional advantage is that the silver staining can be removed, allowing further downstream mass spectrometry analysis.
Zhang
Meiqin
M
Laboratoire d'Electrochimie Physique et Analytique, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland.
Wittstock
Gunther
G
Shao
Yuanhua
Y
Girault
Hubert H
HH
D004563:Electrochemistry; D004586:Electrophoresis / Q000379:methods; D007782:Lactoglobulins / Q000032:analysis; D013058:Mass Spectrometry / Q000379:methods; D008855:Microscopy, Electron, Scanning / Q000379:methods*; D009211:Myoglobin / Q000032:analysis; D036103:Nanotechnology / Q000379:methods*; D010084:Oxidation-Reduction; D011145:Polyvinyls / Q000737:chemistry*; D011506:Proteins / Q000032:analysis*; D012680:Sensitivity and Specificity; D012709:Serum Albumin / Q000032:analysis; D012834:Silver / Q000737:chemistry*; D013194:Staining and Labeling; D005465:Fluorocarbon Polymers
D007782:Lactoglobulins; D009211:Myoglobin; D011145:Polyvinyls; D011506:Proteins; D012709:Serum Albumin; D012834:Silver; C024865:polyvinylidene fluoride; D005465:Fluorocarbon Polymers