Colloidal gold
Colloidal gold nanoparticles have been used by artists for centuries because they interact with visible light to produce bright colors. Recently, this unique photoelectric property has been researched and applied in high-tech fields such as organic solar cells, sensor probes, therapeutic agents, drug delivery systems in biological and medical applications, electronic conductors, and catalysis. The optical and electronic properties of gold nanoparticles can be adjusted by changing their size, shape, surface chemistry and aggregation state.
The colloidal gold solution refers to a gold sol with a dispersed phase particle diameter between 1 and 150 nm. It belongs to a heterogeneous heterogeneous system, and the color is orange to purple. The use of colloidal gold as a marker for immunohistochemistry began in 1971. Faulk et al. Used electron microscopy immunocolloidal gold staining (IGS) to observe Salmonella.
Labeled on the second antibody (horse anti-human IgG), an indirect immunocolloid gold staining method was established. In 1978, geoghega discovered the application of colloidal gold markers at the light mirror level. The application of colloidal gold in immunochemistry is also called immunogold. Afterwards, many scholars further confirmed that colloidal gold can adsorb proteins stably and rapidly, and the biological activity of the protein has not changed significantly. It can be used as a probe for precise positioning of cell surface and intracellular polysaccharides, proteins, polypeptides, antigens, hormones, nucleic acids and other biological macromolecules. It can also be used for daily immunodiagnosis and immunohistochemical localization, thus in clinical diagnosis And the application of drug detection and other aspects have been widely valued. At present, immunogold staining at the electron microscope level (IGS), immunogold staining at the light microscope level (IGSS), and speckle immunogold staining at the macroscopic level are increasingly becoming powerful tools for scientific research and clinical diagnosis.