Human serum containing anti-La antibodies stained the nuclei of HEp-2 cells in a finely speckled pattern (A and C). DAPI staining in panels B and D indicate the location of nuclei. Note that in dividing cells (white arrow), anti-La antibodies did not react with chromosomes. Human serum containing anti-La antibodies was provided by the Centers for Disease Control and Prevention from the international ANA reference serum panel.
