| A | B |
|---|
| Homogeneous EIA | Patient antigen concentration is directly proportional to the signal. |
| Heterogeneous | In a noncompetitive immunoassay, the concentration of patient antigen is directly proportional to the signal. In a competitive immunoassay, patient antigen concentration is indirectly proportional to the signal. |
| Competitive | Inverse ratio: The more patient antigen is present, the less label is detected. |
| Noncompetitive, indirect ELISA for antibody detection | All patient antibody is allowed to bind. Amount of label is directly proportional to the amount of patient antibody present. |
| Capture or sandwich | All patient antigen is allowed to bind. Amount of label is directly proportional to the amount of patient antigen present. |
| Enzyme-multiplied immunoassay technique (EMIT | All patient antigen is allowed to bind. Amount of signal generated is directly proportional to the amount of patient antigen present. |
| Direct immunofluorescence | If fluorescence is detected, patient sample is positive for the antigen. Fluorescence on cell surface indicates that the cell is positive for the antigen. |
| Indirect immunofluorescence | If fluorescence is detected, antibody or antigen is present in the sample, and the test is positive |
| Fluorescence polarization | When patient antigen binds to antibody, less reagent-labeled antigen binds, and less polarized light will be detected. Inverse ratio between patient antigen and amount of polarization. |
| Rapid Immunochromatographic | Presence of test line may indicate either positive or negative result, depending on manufacturer design. |
