Scanning immunoelectron microscopy markers.

Ultrastructural analysis of the cell surface and of membrane components such as antigens or receptor sites by scanning immunoelectron microscopy (immuno-SEM) has been the subject of extensive investigation during the past few years. We review the various immunologic and cytochemical techniques applied to SEM, which have employed latex particles, viruses, bacteriophages, protein A, ferritin, gold granules, hemocyanin and peroxidase as markers, and the advantages and disadvantages of these techniques. From current data, it is clear that immuno-SEM has much to offer in determining the distribution of specific cell surface sites and in positive and unambiguous identification of cell types in heterogeneous cell populations.