Anti-DNA antibodies stain the nuclei of HEp-2 cells in a homogeneous pattern

Human serum containing anti-DNA antibodies stain the nuclei of HEp-2 cells in a homogeneous pattern (A and C). DAPI staining in panels B and D indicates the location of nuclei. In dividing cells (indicated by white arrow in C and D), staining is associated with the separating chromosomes. The anti-DNA antibody reference serum was obtained from the Centers for Disease Control repository of ANA standards.