pUL52 is 75-kDa protein encoded by essential Human cytomegalovirus (HCMV) gene UL52. This protein shows true late kinetics. Preferentially is located in the nucleus surrounding the viral replication and packaging compartments, though it can be found in cytoplasm as well. Absence of this gene doesn’t affect viral DNA replication but it prevents cleavage-packaging of genome concatemers (J Virol, (2008) 82, 2065-78)). Our anti-UL52 antibody UL52N.03 (described in J Virol (2013) 87, 1720–1732) works in ELISA (on immunogen) and each LOT is validated for Western blot (of HCMV infected cell lysates), where it specifically recognizes a protein species of ~76 kDa, which corresponds well to the predicted size.