A transmission electron microscope includes an electron beam source to generate an electron beam. Beam optics are provided to converge the electron beam. An aberration corrector corrects the electron beam for at least a spherical aberration. A specimen holder is provided to hold a specimen in the path of the electron beam. A detector is used to detect the electron beam transmitted through the specimen. The transmission electron microscope may operate in an incoherent mode and may be used to locate a sequence of objects on a molecule.