Scanning Electron Microscopy of Red Cell Agglutination

Scanning electron micrography of red cells agglutinated by various blood group antibodies has shown that the agglutinates formed are of two completely different morphologic types. Type I, obtained with anti‐A sera (IgM and IgG) as well as with anti‐A1 lectin, consists of interlaced, crenated and spiculated cells, while type II, obtained with anti‐D sera (complete and incomplete) consists of densely but randomly packed smooth, discoid cells. Papain treatment results in indented, spheroid cells with a much corroded surface. Coombs‐type antiglobulin agglutinates consist of spheroid cells, the coating of which tends to form a continuous envelope, interconnecting several cells. The influence of heterogeneic and of viral agglutinins is also illustrated.