['To compare the predictive values of enzyme-linked immunosorbent assays (ELISAs) and indirect immunofluorescence (IIF) techniques for the detection of M2 anti-mitochondrial antibodies.', "Commercial ELISAs are widely available for the detection of anti-mitochondrial antibody subtypes in primary biliary cirrhosis (PBC). We compared the results from two ELISAs (one recombinant, one purified antigen) with those from two IIF methods in a well-defined cohort of PBC patients and in patients with systemic lupus erythematosus, Sjögren's syndrome, sicca syndrome, systemic sclerosis, rheumatoid arthritis and blood donor controls.", 'There was good correlation between a rodent substrate IIF and ELISA A (r=0.9134), but poor correlation with ELISA B (r=0.5999), which produced many false-positive results in the control population. We show that rodent IIF alone or human epithelial cell (HEp-2000) screening with confirmation by ELISA produce similar predictive values for PBC and require lesser degrees of skilled interpretation of IIF patterns.'] Is detection of serum M2 anti-mitochondrial antibodies by enzyme-linked immunosorbent assay potentially less specific than by immunofluorescence?