Figure 2.
Schematic of ELISA assay to determine efficiency of capturing PSA, detection antibody, and streptavidin. Row 1, ELISA assay of sample with known concentration of biotin-labeled PSA. Row 2, ELISA assay of supernatant from row 1 assay. Reduction in ELISA signal indicates how much biotin-labeled PSA is captured by anti-PSA beads. Row 4, ELISA assay of unlabeled PSA at same concentration as PSA in row 1, followed by biotin-labeled detection antibody. Comparing ELISA signal in row 4 vs. row 1 indicates how efficiently biotin-detection antibody is captured by bound PSA.
