Turning precipitation into agglutination: coating a soluble antigen onto which carrier(s) converts a precipitation reaction into a more sensitive agglutination assay?

Introduction / Context:
Precipitation requires visible lattice formation between soluble antigens and antibodies. By adsorbing antigens onto large particles (cells or synthetic beads), the same interaction becomes agglutination, dramatically improving visibility and sensitivity in serologic testing.

Given Data / Assumptions:

• Soluble antigens can be attached to various carriers.
• Agglutination readouts are easier to detect than faint precipitates.

Concept / Approach:
Attaching antigens to RBCs (hemagglutination), latex, or bentonite creates multivalent platforms. Even low concentrations of specific antibodies can cross-link many particles, producing macroscopic clumps. Thus, multiple carriers are valid choices to convert precipitation into agglutination.

Step-by-Step Solution:

Verification / Alternative check:
Laboratory manuals list all three carriers as valid supports in particle agglutination assays for antigen or antibody detection.

Why Other Options Are Wrong:

• Single-carrier choices are incomplete since all listed carriers work.
• None of these: Contradicts standard serology practice.

Common Pitfalls:

• Assuming only latex works; RBCs and bentonite are classic supports as well.

Final Answer:
All of these