Abstract
The events occurring at the cell membrane during reactive lysis were studied by electron microscopy, using purified complement components (generously donated by Drs. W. Kolb, E. Podack and H. J. Müller-Eberhard, Scripps Clinic). At the 
stage, no particles were seen attached to the membrane after preparation for E.M. At the 
stage, a foliaceous particle was seen attached to the membrane surface, with a narrow stalk and two to three arms extending outward. At the 
stage, the particles appeared larger and possessed up to six arms. None of these stages showed any lesions previously described as “complement holes.” However, the 
stage showed many typical complement lesions, presumably due to the rearrangement of the structure of the particles.
The lesions in profile appeared to show channels that penetrated all or part of the thickness of the cell membrane; however, such observations must be interpreted with caution, as the relation of the E.M. negative staining image of the membrane to the biologic structure has not been clarified.
