Final answer:
In agglutination tests, antibodies agglutinate whole-cell antigens, forming visible clumps. This typically takes place on microtiter plates and is essential in identifying bacterial serovars.
Step-by-step explanation:
In agglutination tests, antibody cross-links whole-cell antigens, forming complexes that settle out and form visible clumps in the test chamber. The antibodies can agglutinate cells or large particles into a visible matrix. These tests are often done on cards or in microtiter plates that allow multiple reactions to take place side by side using small volumes of reagents. Antigens coated onto particles like latex beads can enhance visualization of agglutination, which is a common method used for identifying serovars of bacteria and viruses in both direct and indirect agglutination assays. Flocculation assays are related, but involve insoluble antigens such as lipids leading to flocculation rather than precipitation.