Produced by the National Institute of Allergy and Infectious Diseases (NIAID), this highly magnified, digitally colorized transmission electron microscopic (TEM) image highlights the particle envelope of a single, spherical shaped, Middle East respiratory syndrome coronavirus (MERS-CoV) virion, through the process of immunolabeling, the envelope proteins, using rabbit HCoV-EMC/2012 primary antibody, and goat anti-rabbit 10nm gold particles.