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Ouchterlony plate demonstrating different types of antinuclear
antibodies Ouchterlony double immunodiffusion where 6 SLE sera were tested against a soluble extract of calf thymus nuclear extract ie. containing multiple nuclear antigens, in the upper central well and against soluble double strand DNA in the lower central well. Sera in wells 3 and 4 have antibodies to DNA. Sera in wells 1, 2, 5 and 6 did not have antibodies to DNA but had antibodies to the Sm antigen