ABSTRACT
Immunological identification may be applied to a sample in which the presence of a certain bacterium is suspected. This requires either a large amount of the agent in the sample or a high sensitivity of the method, although a lower sensitivity may be accepted if identification is applied to pure cultures. In setting up the method (e.g., when pretesting the antibodies), attention is normally paid to avoiding cross-reactions with closely
4.1 Antigens and antibodies ........................................................................ 71 4.2 Agglutination .......................................................................................... 72 4.3 Immunofluorescence techniques .......................................................... 73
4.3.1 Diagnosing the presence of bacteria in a sample ................... 73 4.3.2 The immunofluorescence assay ................................................ 75
4.4 Immunoenzymatic staining .................................................................. 77 4.5 Enzyme-linked immunosorbent assay ................................................ 79
4.5.1 Principles ...................................................................................... 79 4.5.2 The microtiter plates ................................................................... 79 4.5.3 The antigen .................................................................................. 82 4.5.4 Antibodies, enzymes, and substrates ...................................... 82 4.6.5 Coating the wells ........................................................................ 84 4.5.6 Blocking the wells ....................................................................... 85 4.5.7 Performing the assay .................................................................. 86 4.5.8 Control sera .................................................................................. 87 4.5.9 Interpretation of the OD value .................................................. 87
4.6 Immunoblotting ...................................................................................... 87 4.7 Multiplex .................................................................................................. 89 References .......................................................................................................... 90
related bacteria, while bacteria with a more distant relationship would not be tested. One should, therefore, never try to identify a pure culture by an immunological method if the culture has not been subjected to basic tests, and these tests have allocated the isolate to the group including that bacterium against which the antibody is directed.
