The AFM image of ricin (plant ribosome-inactivating protein type II). The image was obtained using a super sharp DLC probe, allowing details of the ricin substructure to be discerned. Molecules are deposited on the mica in different orientations; some well oriented molecules clearly show the A-subunit domain (fat arrows) and the two B-subunit domains (fine arrows).

The sample was kindly given by A.G. Tonevitsky and I. I. Agapov, Institute for transplantation and artificial organs, Moscow, Russia.
Image courtesy of M.Savvateev, NT-MDT, Moscow, Russia mihail.savvateev@mail.ru.