Graphical representation of ELISA results. Reactivity of Fabs (10 μg/ml) to monomeric rgp120 from various SIV and HIV-2 isolates and a panel of irrelevant protein antigens. Fabs 101, 102, 103, 201, 202, 203, and 204 were selected by panning of the library against monomeric SIV rgp120, whereas 1LNRh544 is a randomly picked clone from the unscreened library.