FIG. 2.

In vitro neutralization of DEN strains by neutralizing MAbs DA6-7 and DA11-13. The ascitic fluids containing DA6-7 and DA11-13 were purified using a protein G Sepharose column. (A) The neutralizing activities of the purified MAbs were tested by PRNT against DEN-1 strain 766733. (B) Inhibition of DEN infection by neutralizing MAbs, using an immunofluorescence assay. DEN-1 strain 766733 was incubated with 100 μg/ml of neutralizing or control MAb for 1 hour and then used to infect BHK-21 cells. The DEN-infected cells were detected with the 4G2 MAb.