You are designing a sandwich ELISA to detect Borrelia burgdorferi OspC antigen in patient serum. Which design choice below is most appropriate for capture/detection reagents and plate controls to ensure reliable diagnosis across multiple samples?

• A. Coat wells with enzyme-linked detection antibody to avoid a separate conjugation step, add substrate before adding patient sample so the plate is pre-charged, and rely on historical plate performance as a control rather than including fresh positive or negative controls on the same plate.
• B. Coat wells with whole Borrelia lysate to capture any serum component, use the same monoclonal antibody as both capture and detection to save reagent costs, and include only patient samples without any positive controls to avoid cross-contamination from standard proteins.
• C. Coat wells with a high-affinity monoclonal antibody specific to OspC as capture, use a non-overlapping polyclonal or different-epitope monoclonal enzyme-conjugated detection antibody; include wells for a known positive antigen control, negative serum control, blank wells with substrate only, and a dilution series of recombinant OspC as a standard curve across the plate layout.
• D. Do not use a capture antibody; instead coat wells with patient serum proteins and detect antigen directly with a detection antibody; include an irrelevant viral antigen as the positive control to ensure general assay competence.

Answer: (C)