Human autoantibody against Scl-70 antigen, buffered with 0.01M phosphate, 0.13 M NaCl, 0.02% NaN3. For use in ENA Ouchterlony kit. Shows only the Scl-70 precipitate band when tested using double immunodiffusion against rabbit thymus extract (RTE-1000). Specificity is verified by identity of precipitation with CDC-AF reference serum. Titer will vary with test system; however, undiluted antibody shows a strong Scl-70 precipitate band.