Figure 3.

In vitroRV neutralization properties of larva-derived single-domain antibodies determined by a fluorescent focus reduction assay. Different amounts of VHHs were mixed with 100 fluorescent focus-forming units (FFU) of human RV strain Wa (SbI, P [8]G1). The antibody concentration that generates an 80% reduction of fluorescent focuses was considered protective. The assay also included 3B2 and 2KD1 purified from E. coli as positive controls and the total soluble protein of unrelated baculovirus-infected larvae as a negative control.