Final answer:
On the surface of a latex particle, antigens are attached to detect specific antibodies in a patient's serum, while antibodies are attached to detect specific antigens in the same context.
Step-by-step explanation:
On the surface of a latex particle, either an antigen or an antibody can be found, depending on the purpose of the test being performed. For instance, to detect antibodies in a patient's serum, antigens are attached to the latex beads, which will then agglutinate in the presence of specific antibodies in the serum, indicating the antibodies' presence. In a reverse test, to identify antigens in a patient's serum, antibodies (commonly monoclonal antibodies or mAbs) are attached to the latex beads. When this complex is mixed with the serum, the antigens in the serum that are specific to these immobilized antibodies will cause the latex beads to agglutinate.