After four rounds against the two rNP analytes, the robotic screening system automated a final round of screening against diluted, pooled, positive patient samples in the round's positive tests, and diluted, pooled, negative patient samples in the round's negative tests (Round 5). This last round screened the 26 antibodies which had not been previously dropped due to poor performance and for which we had sufficient stock (676 pairs). The purpose of this final screen was two-fold: (1) determine if relative performance of top pairs from rounds against the rNP analytes persisted in a round against clinical samples, and (2) we had the opportunity to compare, head-to-head, the relative performance of all α-NP antibody pairs. The only antibody pairs excluded from this round performed poorly in several prior rounds (rankings for all pairs in all rounds in Table ). Additionally, three newly available antibodies were screened in the clinical pool round for the first time. Antibody pairs containing these antibodies performed well, appearing as a top-five pair twice (pair indices 736 and 608,Table ) and nine times in the top 20 (pair indices 736, 608, 686, 30, 689, 708, 815, 416, and 171, Table ). The five best antibody pairs against the diluted clinical sample pool (Round 5) are listed in Table along with the top five pairs against GM-rNP (Round 1) and against the lowest-concentration of AB-rNP (Round 4). The top antibody pairs against the three different analyte sources are highlighted in the scatter plots (S-N vs. S/N) in Figure , and in the average of S-N and S/N rankings in Table . Nine of the top-20 antibody pairs screened against GM-rNP and 15 of the top-20 pairs screened against the lowest concentration of AB-rNP were available to be screened against the diluted clinical sample pool. Of these 24 antibody pairs, few performed well in the screen against the diluted clinical sample pool. One of these 24 (pair index 900, Table ) had an average rank (i.e. average of S-N rank and S/N rank) of 24.5 in the clinical sample screen, whereas the average rank of the other 23 pairs ranged from 110 to 671.5, with a median value of 336.5 (where the total number of pairs in this round was 676).