Figure 4
From: Chloroquine is a potent inhibitor of SARS coronavirus infection and spread
NH 4 Cl inhibits SARS-CoV during pre or post infection treatment. NH4Cl was added to the cells either before (A) or after (B) infection, similar to what was done for chloroquine in Figs 1 and 2. Antigen-positive cells were counted, and the results were presented as in Fig. 1B.