ELISA tor Legionnaires' Disease - Antibody and Antigen Detection Systems: An Interim Report 



1st layer 



2nd layer 



3rd layer 



4th layer 



1. Antibody (Ab) to LDB, adsorbed to plastic well of a tray 



2. Wash 



Specimen containing LDB antigen (Ag) diluted in normal goat 

 serum; prepare a duplicate specimen diluted in anti-LDB goat 

 serum in another well 



4. Wash 



5 . Rabbit antibody (RAb) to LDB. Will bind to any antigen bound 

 in previous step 



6. Wash 



7. Enzyme-labeled antibody (EAb) to rabbit IgG. Goat anti-rabbit 

 will bind to rabbit anti-LDB being held by LDB antigen from 

 specimen 



8. Wash 



develop color 



9. Substrate(s) to make reaction visible. Any enzyme bound in the 

 complex will convert substrate to a detectable color. 



Figure 2. ELISA: 4-layer antigen detection system 

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