Transmission Electron Microscopy Observation of Antibody

High resolution electron microscopy (TEM) observation of an antibody, which is stained with sodium phosphotungstate solution, has been performed at accelerating voltage of 200 kV. In order to reduce background noise due to superposed substrate image, we observed antibodies standing on the edge of the mica substrate in the vacuum. Two typical images have been taken successfully. One shows Y-shaped contrast. The other image, which is thought to be a side view image, shows constricted part corresponding to hinge region. Both lengths of Fab (fragment, antigen binding) region and Fc (fagment, crystallizable) region are measured directly by referring lattice fringes of mica.