VZV ORF23 encodes a 24 kDa small capsid surface protein that localizes primarily to cell nuclei during infection and is not essential for viral replication in cell culture, even though its absence disrupts the capsid assembly. VZV ORF23 protein is located on the outer side (tips) of nucleocapsid hexons and is apparently required for the transport of major VZV capsid protein, encoded by ORF 40, to nuclei of VZV infected cells. The absence of ORF23 encoded protein prevented the VZV infection of human skin xenografts, indicating that ORF23 is required for VZV pathogenesis in vivo, making the corresponding protein an attractive target for antiviral biopharmaceuticals, including monoclonal antibodies, against VZV. Our anti-VZV ORF23 antibody VZ 23.07 works in ELISA (on immunogen), IF (on VZV infected cells) and each LOT is validated for Western blot (of VZV infected cell lysates) (described in J Virol. 2013 Jun;87(12):6943-54.).