Sensitive and specific immunohistochemistry protocols for detection of SARS-CoV-2 nucleocapsid and spike proteins in formalin-fixed, paraffin-embedded COVID-19 patient tissues
Abstract Human coronavirus disease 2019 (COVID-19) is a life-threatening and highly contagious disease caused by coronavirus SARS-CoV-2. Sensitive and specific detection of SARS-CoV-2 virus in tissues and cells of COVID-19 patients will support investigations of the biologic behavior and tissue and cell tropism of this virus. We identified two commercially available affinity-purified polyclonal antibodies raised against Nucleocapsid and Spike proteins of SARS-CoV-2 that provide sensitive and specific detection of the virus by immunohistochemistry in formalin-fixed, paraffin-embedded tissue. Protocols are presented that are mutually validated by matched detection patterns of virus-infected cells in autopsy lung tissue of COVID-19 deceased patients by the two distinctly different antibodies. Negative controls include autopsy lung tissue from patient who died from non-COVID-19 respiratory disease and control rabbit immunoglobulin. SARS-CoV-2 detection in human tissues will provide insights into viral tissue and cell distribution and load in patients with active infection as well as provide insight into clearance of virus in late COVID-19 disease stages.