Abstract: Antinucjear antibodies (ANA) were studied in 59 patients with different connective tissue diseases by indirect immunofluorescence (FF) with rat organ imprints, human cancer imprints and HEp-2 cells as substrates. Sensitivity and specificity of human cancer imprints for detection of ANA were higher than animal organ substrates. The finding of anti-centromer.antibody by imtnunofluorescence (IF) with human cancer imprints as substrate was confirmed by IF technique using HEp-2 cells.