Immunoelectron microscopy

IEM

1. IMMUNOELECTRON MICROSCOPY

2. Immune electron microscopy  is a variation of electron microscopy. It is applied for diagnosis of many viral infections.  IEM was developed as a diagnostic aid for detecting and identifying transmissible gastroenteritis virus and rotavirus (reovirus-like agent) in faecal and intestinal contents from cases of gastroenteritis in young pigs.  IEM is one of the fastest and most sensitive methods for the detection and diagnosis of viruses. This technique is based on formation of immune complexes of the virus with its corresponding antibody.

3. IEM is used to localize molecules at the ultrastructural level by labelling them with specific antibodies, which are visualized by electron-opaque markers (colloidal gold particles) attached to them. The effect is to produce an electron-dense label at the site of the antigen-antibody reaction. When the antigen is located inside of the cell, then transmission electron microscopy is required to see it. The labelling can be done pre-embedding or post-embedding. When the antigen in question is located on the surface of the specimen, scanning electron microscopy can be used to see it. The electron dense label can then be viewed using the back scatter image on an appropriately equipped microscope.