Figure 1
Immunofluorescence histochemistry depicting the Sm staining pattern on HEp2 cells using autoantibodies to Sm in the sera of patients with systemic lupus erythematosus. Sm antigen has been identified as a component of mRNA splicing particles distributed in the nucleoplasm in the size and location shown here. This pattern has been called nuclear speckles. The cytoplasm is nonreactive with the antibody and the nucleolar domains contain a few small speckles.