Double-staining methods at the ultrastructural level applying colloidal gold conjugates.

Several double gold-labeling methods have been reviewed, and our own results of applying some of these methods have been included. Of the six double-staining methods tested, four gave satisfactory results (indirect double immunogold staining method, two-face protein A-gold staining method, two-face amplified protein A-gold staining method, and formaldehyde blockade protein A-gold staining method). The other two techniques (sequential double protein A-gold staining method and formaldehyde blockade amplified protein A-gold staining method) showed cross-reaction between the first and second staining sequence.