Summary The fluorescent patterns of autoantibodies to mitochondria, endoplasmic reticulum and ribosomes are described. Mitochondrial autoantibodies can be now divided in 10 types, microsomal antibodies at least in 3 types. Using rat renal tissue sections the typical fluorescent pattern of new antimitochondrial antibodies were: type 7, distal tubulus and third portion of proximal tubules, type 8 distal tubules, only, type 9 first and second portion of proximal tubules, type 10 strong reaction of distal and third portion of proximal tubules. The new pattern of ribosomal antibody is characterized by a cytoplasmic staining of rat hepatocytes especially in the central area of the liver lobule. The heterogeneity of cytoplasmic autoantibodies can be used as a diagnostic marker in different pathological conditions, if the different staining patterns is taken into account.