CD40LG and COVID-19: Each test strip generally consists of (i) a sample pad to add patient samples, (ii) a conjugate pad containing COVID-19 antigen conjugated with gold nanoparticles (gold-COVID-19) and gold-rabbit IgG, (iii) a nitrocellulose membrane that consists of a control line coated with goat anti-rabbit IgG, an IgG test line coated with anti-human IgG, an IgM test line coated with anti-human IgM as well as (iv) an absorbent pad that absorbs waste (Li et al., 2020; Sheridan, 2020).