The following diagnostic tests are useful for corresponding purposes except -: (A) Ziehl - Neelsen staining - Detection of mycobacteria, (B) Immunofluorescence - Detection of Influenza virus, (C) Specific IgM antibodies - Immunity against Rubella, (D) Specific IgM antibodies - Detection of acute infection
Answer is C. For any infection (including rubella) IgM antibody alone, without IgG means current (acute) infection.


Ziehl Neelsen staining is used for mycobacteria.


Rapid diagnosis of influenza is made by demonstration of viral antigen in specimens by Immunofluorescence.