To adapt the classic ELISpot assay to measure the productive reservoir in primary samples from individuals with HIV-1 infection, we formulated a combined coating of the plates to reactivate the latent reservoir using anti-CD3 and anti-CD28 antibodies and to simultaneously capture the antigen produced by the cells with an anti-p24 antibody (Fig. 1A). The gene discussed is CD28; the disease is HIV-1 infection.