Coronavirus disease 2019 (COVID-19) is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). When humans are exposed to the virus, they can acquire immunity by forming IgG antibodies against the spike protein on the viral envelope. It is vital to know which individuals are already exposed to the virus by testing for the human IgGs that are present in the serum against the viral spike protein. This reagent kit is developed to help develop other diagnostic tests and assays to detect the human IgGs against SARS-CoV-2 in the serum. The kit contains the key reagents necessary (spike protein and antibodies), and these reagents can be used with any ELISA-compatible microplates, and other generic buffers and reagents for HRP detection.