Dot blot assay for detection of antidiacyltrehalose antibodies in tuberculous patients

A simple dot blot test with diacyltrehalose (DAT) as the antigen was develo ped to detect anti-DAT antibodies in tuberculous patients. To enhance antig en-antibody reaction detection, rabbit serum raised against human immunoglo bulins was used prior to incubation with a protein A-colloidal gold complex . With the dot blot system, it was possible to obtain a sensitivity similar to that of enzyme-linked immunosorbent assay (ELISA) and a specificity of 97.14%, versus a specificity of 94.29% by the ELISA, We conclude that this simple and fast assay could be used in places where ELISA equipment is not easy available and that it might also be applicable with other Mycobacteriu m tuberculosis immunogenic antigens.