Visualization of polymercurimethane-labeled for bacteriophage in the scanning transmission electron microscope

Each of the 2700 coat proteins of fd bacteriophage was labeled with tetrakis(acetoxymercuri)methane (TAMM) or aquoglycylmethionineplatinum(II). The TAMM-labeled specimens reveal striking bright spots in the scanning transmission electron microscope which arise from clustering. Measurements of mass show increases consistent with the addition of four mercury atoms or one platinum atom, respectively, to each coat protein.