This product has only the Anti-La/SS-B precipitin band when tested using double immunodiffusion against rabbis thymus extract. The titer obtained will vary with the test system; however, undiluted antibody shows a strong Anti- La/SS-B precipitin band.
The specificity is verified by a precipitin line of identity with the CDC-AF reference serum. This product shows no reactivity at a dilution of 1:100 when tested against purified nRNP, Sm, Scl-70, Jo-1, Mitochondrial, or Ribosoma P antigens in an ELISA system designed to detect IgG antibody. These sera are powerfully positive in an Anti-La/SS-B ELISA system.