Severe acute respiratory syndrome (SARS) was the first new infectious disease identified in the twenty-first century. It is a viral respiratory disease caused by severe acute respiratory syndrome coronavirus (SARS-CoV-1). The first known cases occurred in November 2002, and the syndrome caused the 2002-2004 SARS outbreak. Since 2004, no cases of SARS-CoV-1 have been reported worldwide. A virus very similar to SARS-CoV-1 was discovered in late 2019. This virus, named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is the causative pathogen of , the spread of which started the pandemic.SARS-CoV-1 attaches to the host cell surface before entering the cell. The Spike protein on the virus recognizes and binds to the Angiotensin-Converting Enzyme 2 (ACE2) receptor found on the surface of human airway epithelia as well as lung parenchyma. Drugs targeting the interaction between the Spike protein of SARS-CoV-1 and ACE2 may offer protection against the viral infection.The Spike (SARS-CoV-1) Pseudotyped Lentiviruses were produced with SARS-CoV-1 Spike (Genbank Accession #YP_009825051.1) as the envelope glycoprotein instead of the commonly used VSV-G. These pseudovirions contain the firefly luciferase gene driven by a CMV promoter, therefore, the spike-mediated cell entry can be measured via luciferase activity. The Spike (SARS-CoV-1) pseudovirus can be used to measure the activity of a neutralizing antibody against SARS-CoV-1 in a cellular context, using a Biosafety Level 2 facility.The Spike (SARS-CoV-1) Pseudotyped Lentiviruses has been validated for use with target cells ACE2-HEK293 (which overexpress ACE2; BPS Bioscience #79951).