Significant titres of circulating antibodies reacting with a wide range of normal tissue components occur with variable frequency in several liver disorders. Those that are of particular relevance to liver disease include the antinuclear (ANA), smooth muscle (SMA), liver–kidney microsomal (LKM), antimitochondrial (AMA), and antineutrophil cytoplasmic (ANCA) antibodies. In some conditions, such as autoimmune hepatitis (AIH) and primary biliary cirrhosis (PBC), they form part of the diagnostic criteria.1 ,2 Their presence in others, such as chronic viral hepatitis, may serve to confuse. These autoantibodies are routinely detected by indirect immunofluorescence on sections of appropriate tissues or isolated cells and an experienced eye is required for interpretation of the different patterns of immunofluorescent staining. It has long been recognised, however, that antibodies giving apparently similar staining patterns often react with different antigens in the substrates used for their detection. In order to improve the …