ADA and infection: To determine whether increasing cell density of TZM-gfp similarly interfered with susceptibility to infection by cell-free HIV viral stocks, we seeded serial twofold dilutions of TZM-gfp cells in a 5 × 5 matrix of 2 μL drops in coverslip dishes (ibidi), allowed them to adhere, and challenged the whole dish with HIV-1 ADA virions (Fig. 3I).