Virus neutralization by HMAbs. Approximately 100 FFU of virus were incubated with serial dilutions of purified monoclonal antibody. Virus mixtures were allowed to infect LLC-MK-2 cells and then incubated at 37C. Virus foci were detected using anti-DENV E protein MMAb E60. Results are expressed as pooled data from two independent experiments with three replicates each. A HMAb 2.3D. B 3.6D. C 4.8A. D 4G2. E 3H5.