Backscattered electron (BSE) image of isolated mitochondria from cultured bovine lymphocytes. These mitochondria are either in the late stage of dividing, or an early stage of fusing. White dots are 18 nm gold particles conjugated to an antibody against Mannheimia haemolytica leukotoxin. Accelerating voltage was 5kV. Dhammika Atapattu, School of Veterinary Medicine, Univ. of Wisconsin, unpublished with permission.