Figure 4

Results of checkerboard titration assays used to optimize the peptide concentration and serum dilution. Standard positive (P) and standard negative (N) serum samples were serially diluted twofold, and the coating concentration was varied. A For the mAb 3A9 bELISA, the optimal conditions were a peptide coating concentration of 50 ng/well and a serum dilution ratio of 1:2. Under the optimal conditions, the best signal-to-noise ratio (N/P) was 15. B For the mAb 4F7 bELISA, the optimal conditions were a peptide coating concentration of 100 ng/well and a serum dilution ratio of 1:2. Under the optimal conditions, the best signal-to-noise ratio (N/P) was 16.