Fig. 4.

Lateral flow immunoassay for detecting anti-SARS-CoV-2 antibodies. Samples move via capillary flow on the NC membrane. When anti-SARS-CoV-2 antibodies are present, they bind to the labeled antigen and continue to move until they are captured by the immobilized antihuman antibodies. The presence of the captured antibody–antigen complex is visualized as a colored test band. The labeled control antibodies comigrate until they are captured at the control band. Reprinted with permission from Ref. [81]. Copyright 2020 American Chemical Society.