Nanogold Immunodetection Detection Systems for the Identification of Autoantigens by Western Blotting

Nanogold-conjugated immunodetection systems are now widely and commercially available for use in a number of research applications including electron microscopy, light microscopy, and western blotting. Nanogold clusters are small, uniform in size, and stable, unlike gold colloids historically used in protein detection. Covalent linkage of nanogold particles to secondary antibodies prevents dissociation of the gold particles during the staining process, making protein detection reliable, antigen specific, and highly sensitive. Nanogold labeling is extremely versatile and can be used in conjunction with other staining methodologies including Alexa Fluor immunofluorescence detection to perform coupled staining procedures. Silver enhancement increases the limits of sensitivity for nanogold staining, thus improving detection signals for antigens with reduced expression levels. Herein, we describe the use of nanogold-silver detection as an immunodetection system for standard western blotting of autoantigens.