Table 1. Summary of recovery of recombinant anti-human TNFR2 antibodies from antigen-specific rabbit plasma cells.

Number of bone marrow cells analyzed	Number of hTNFR2-specific plasma cells isolated	Number of VH and VL cognate gene pairs recovered	Number of hTNFR2-specific recombinant antibodies (via TAP)
3.8 × 106	96	72	50

Bone marrow preparations from 4 immunized rabbits were analyzed via the fluorescent foci method using biotinylated human TNFR2 extracellular domain as the target antigen. Following RT-PCR, recoveries of heavy (VH) and light (VL) chain variable region gene pairs were determined by agarose gel electrophoresis of the secondary PCR products. Binding of recombinant antibody to TNFR2 was determined using supernatants from HEK-293F cells which had been transiently co-transfected with heavy and light chain TAP products. The assay was performed using a fluorescence-based homogeneous format with biotinylated human TNFR2 immobilised on Superavidin beads and an anti-rabbit Fcγ-Cy5 secondary reagent.