1.   We have made retrovirus particles displaying a functional antibody fragment.

2.   The cells isolated by panning were heavily coated with the beads, indicating that a functional antibody fragment was displayed on the surface of the transfected cells.

3.   This suggested that the functional antibody fragment could be incorporated into virion particles and displayed at their surface.

4.   As proof that the functional antibody fragment was displayed on infectious retroviral particles, the novel IRISA assay was developed.