Microplate and dot immunoassays for the serodiagnosis of tuberculosis

A simple dot enzyme immunoassay based on the recognition of serum IgG antibody to a 30,000 dalton native antigen purified from culture filtrates of Mycobacterium tuberculosis was developed and compared with a standard plate enzyme-linked immunosorbent assay in the serodiagnosis of tuberculosis. The previously described favorable test characteristics of plate enzyme-linked immunoassay were confirmed; although the dot enzyme immunoassay was promising, it was less satisfactory. Dot enzyme immunoassay may have its most promising use as a screening test for situations of limited technical facilities. Both plate enzyme-linked immunoassay and dot enzyme immunoassay had markedly reduced sensitivities in persons with human immunodeficiency virus infection.