The Flowflex SARS-CoV-2 rapid antigen test is a lateral flow chromatographic immunoassay for the qualitative detection of the nucleocapsid protein antigen of SARS-CoV-2 from nasal and nasopharynx swab samples (nasal swab) that a healthcare provider suspects to have COVID-19 within ...The Flowflex SARS-CoV-2 rapid antigen test is a lateral flow chromatographic immunoassay for the qualitative detection of the nucleocapsid protein antigen of SARS-CoV-2 from nasal and nasopharynx swab samples (nasal swab) that a healthcare provider suspects to have COVID-19 within seven days of the onset of symptoms. The SARS-CoV-2 Rapid Antigen Test can also test samples from people who have no apparent symptoms.