Large-scale recombinant proteins for anti-ID #6 and #17 were generated and these pairings were compared with the original hybridoma reagent pairings in PK assay formats 4 and 6 to confirm the selection of optimal PK assay format and anti-ID pairing (Figure ; Supplementary Table ). PK assay format 4 yielded higher scores relative to assay format 6 indicating this to be the optimal PK assay format for these anti-ID pairings. There was a decrease in sensitivity and signal to noise scores that resulted in a decreased total score for the anti-ID 6-Biotin/Generic-Tag recombinant pairing compared to the hybridoma pairing. However, there was an increase in signal to noise score in the anti-ID #17-Biotin/Generic-Tag recombinant compared to the hybridoma (Figure ). This increased total score resulted in the selection of anti-ID #17-Biotin/Generic-SulfoTag recombinant pairing in PK assay format 4 as the final PK assay (Figure ).